Search the California Content Standards

Title: MS-PS1 Matter and Its Interactions

Performance Expectation: Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes.* [Clarification Statement: Emphasis is on the design, controlling the transfer of energy to the environment, and modification of a device using factors such as type and concentration of a substance. Examples of designs could involve chemical reactions such as dissolving ammonium chloride or calcium chloride.] [Assessment Boundary: Assessment is limited to the criteria of amount, time, and temperature of substance in testing the device.]

Disciplinary Core Idea(s):
PS1.B: Chemical Reactions Some chemical reactions release energy, others store energy. ETS1.B: Developing Possible Solutions A solution needs to be tested, and then modified on the basis of the test results, in order to improve it. (secondary to MS-PS1-6) ETS1.C: Optimizing the Design Solution Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process - that is, some of the characteristics may be incorporated into the new design. (secondary to MS-PS1-6) The iterative process of testing the most promising solutions and modifying what is proposed on the basis of the test results leads to greater refinement and ultimately to an optimal solution. (secondary to MS-PS1-6)

Science & Engineering Practices: Constructing Explanations and Designing Solutions Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.

Crosscutting Concepts: Energy and Matter The transfer of energy can be tracked as energy flows through a designed or natural system.

California Environmental Principles and Concepts:
Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies.

California Common Core State Standards Connections:
ELA/Literacy RST.6-8.3: Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks. WHST.6-8.7: Conduct short research projects to answer a question (including a self-generated question), drawing on several sources and generating additional related, focused questions that allow for multiple avenues of exploration.

DCI Connections:
Connections to other DCIs in this grade-band: MS.PS3.D Articulation across grade-bands: HS.PS1.A; HS.PS1.B; HS.PS3.A; HS.PS3.B; HS.PS3.D

Title: HS-ESS1 Earth’s Place in the Universe

Performance Expectation: Develop a model based on evidence to illustrate the life span of the sun and the role of nuclear fusion in the sun’s core to release energy that eventually reaches Earth in the form of radiation. [Clarification Statement: Emphasis is on the energy transfer mechanisms that allow energy from nuclear fusion in the sun’s core to reach Earth. Examples of evidence for the model include observations of the masses and lifetimes of other stars, as well as the ways that the sun’s radiation varies due to sudden solar flares (“space weather”), the 11-year sunspot cycle, and non-cyclic variations over centuries.] [Assessment Boundary: Assessment does not include details of the atomic and sub-atomic processes involved with the sun’s nuclear fusion.]

Disciplinary Core Idea(s):
ESS1.A: The Universe and its Stars The star called the sun is changing and will burn out over a lifespan of approximately 10 billion years. PS3.D: Energy in Chemical Processes Nuclear Fusion processes in the center of the sun release the energy that ultimately reaches Earth as radiation. (secondary to HS-ESS1-1)

Science & Engineering Practices: Developing and Using Models Develop a model based on evidence to illustrate the relationships between systems or between components of a system.

Crosscutting Concepts: Scale, Proportion, and Quantity The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. Mathematics MP.2: Reason abstractly and quantitatively. MP.4: Model with mathematics. N-Q.1-3: Reason quantitatively and use units to solve problems. A-SSE.1.a-b: Interpret expressions that represent a quantity in terms of its context. A-CED.2: Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales. A-CED.4: Rearrange formulas to highlight a quantity of interest, using the same reasoning as in solving equations. HSN-Q.A.2: Define appropriate quantities for the purpose of descriptive modeling. HSN-Q.A.3: Choose a level of accuracy appropriate to limitations on measurement when reporting quantities.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS1.C; HS.PS3.A Articulation across grade-bands: MS.PS1.A; MS.PS4.B; MS.ESS1.A; MS.ESS2.A; MS.ESS2.D

Title: HS-ESS1 Earth’s Place in the Universe

Performance Expectation: Evaluate evidence of the past and current movements of continental and oceanic crust and the theory of plate tectonics to explain the ages of crustal rocks. [Clarification Statement: Emphasis is on the ability of plate tectonics to explain the ages of crustal rocks. Examples include evidence of the ages oceanic crust increasing with distance from mid-ocean ridges (a result of plate spreading) and the ages of North American continental crust decreasing with distance away from a central ancient core of the continental plate (a result of past plate interactions).]

Disciplinary Core Idea(s):
ESS1.C: The History of Planet Earth Continental rocks, which can be older than 4 billion years, are generally much older than the rocks of the ocean floor, which are less than 200 million years old. ESS2.B: Plate Tectonics and Large-Scale System Interactions Plate tectonics is the unifying theory that explains the past and current movements of the rocks at Earth’s surface and provides a framework for understanding its geologic history. (ESS2.B Grade 8 GBE) (secondary to HS-ESS1-5) PS1.C: Nuclear Processes Spontaneous radioactive decays follow a characteristic exponential decay law. Nuclear lifetimes allow radiometric dating to be used to determine the ages of rocks and other materials. (secondary to HS-ESS1-5)

Science & Engineering Practices: Engaging in Argument from Evidence Evaluate evidence behind currently accepted explanations or solutions to determine the merits of arguments.

Crosscutting Concepts: Patterns Empirical evidence is needed to identify patterns.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.11-12.8: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. WHST.9-10.2: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes. WHST.11-12.2: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes. Mathematics MP.2: Reason abstractly and quantitatively. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS3.B; HS.ESS2.A Articulation across grade-bands: MS.ESS1.C; MS.ESS2.A; MS.ESS2.B

Title: HS-ESS1 Earth’s Place in the Universe

Performance Expectation: Apply scientific reasoning and evidence from ancient Earth materials, meteorites, and other planetary surfaces to construct an account of Earth’s formation and early history. [Clarification Statement: Emphasis is on using available evidence within the solar system to reconstruct the early history of Earth, which formed along with the rest of the solar system 4.6 billion years ago. Examples of evidence include the absolute ages of ancient materials (obtained by radiometric dating of meteorites, moon rocks, and Earth’s oldest minerals), the sizes and compositions of solar system objects, and the impact cratering record of planetary surfaces.]

Disciplinary Core Idea(s):
ESS1.C: The History of Planet Earth Although active geologic processes, such as plate tectonics and erosion, have destroyed or altered most of the very early rock record on Earth, other objects in the solar system, such as lunar rocks, asteroids, and meteorites, have changed little over billions of years. Studying these objects can provide information about Earth’s formation and early history. PS1.C: Nuclear Processes Spontaneous radioactive decays follow a characteristic exponential decay law. Nuclear lifetimes allow radiometric dating to be used to determine the ages of rocks and other materials. (secondary to HS-ESS1-6)

Science & Engineering Practices: Constructing Explanations and Designing Solutions Apply scientific reasoning to link evidence to the claims to assess the extent to which the reasoning and data support the explanation or conclusion. Connections to Nature of Science: Science Models, Laws, Mechanisms, and Theories Explain Natural Phenomena A scientific theory is a substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment and the science community validates each theory before it is accepted. If new evidence is discovered that the theory does not accommodate, the theory is generally modified in light of this new evidence. Models, mechanisms, and explanations collectively serve as tools in the development of a scientific theory.

Crosscutting Concepts: Stability and Change Much of science deals with constructing explanations of how things change and how they remain stable.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.11-12.8: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. WHST.9-12.1: Write arguments focused on discipline-specific content. Mathematics MP.2: Reason abstractly and quantitatively. N-Q.1-3: Reason quantitatively and use units to solve problems. F-IF.5: Relate the domain of a function to its graph and, where applicable, to the quantitative relationship it describes. S-ID.6.a-c: Represent data on two quantitative variables on a scatter plot, and describe how those variables are related.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS2.A; HS.PS2.B Articulation across grade-bands: MS.PS2.B; MS.ESS1.B; MS.ESS1.C; MS.ESS2.A; MS.ESS2.B

Title: HS-ESS2 Earth’s Systems

Performance Expectation: Develop a model to illustrate how Earth’s internal and surface processes operate at different spatial and temporal scales to form continental and ocean-floor features. [Clarification Statement: Emphasis is on how the appearance of land features (such as mountains, valleys, and plateaus) and sea-floor features (such as trenches, ridges, and seamounts) are a result of both constructive forces (such as volcanism, tectonic uplift, and orogeny) and destructive mechanisms (such as weathering, mass wasting, and coastal erosion).] [Assessment Boundary: Assessment does not include memorization of the details of the formation of specific geographic features of Earth’s surface.]

Disciplinary Core Idea(s):
ESS2.A: Earth Materials and Systems Earth’s systems, being dynamic and interacting, cause feedback effects that can increase or decrease the original changes. ESS2.B: Plate Tectonics and Large-Scale System Interactions Plate tectonics is the unifying theory that explains the past and current movements of the rocks at Earth’s surface and provides a framework for understanding its geologic history. Plate movements are responsible for most continental and ocean-floor features and for the distribution of most rocks and minerals within Earth’s crust. (ESS2.B Grade 8 GBE)

Science & Engineering Practices: Developing and Using Models Develop a model based on evidence to illustrate the relationships between systems or between components of a system.

Crosscutting Concepts: Stability and Change Change and rates of change can be quantified and modeled over very short or very long periods of time. Some system changes are irreversible.

California Environmental Principles and Concepts:
Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy SL.11-12.5: Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest. Mathematics MP.2: Reason abstractly and quantitatively. MP.4: Model with mathematics. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS2.B Articulation across grade-bands: MS.PS2.B; MS.LS2.B; MS.ESS1.C; MS.ESS2.A; MS.ESS2.B; MS.ESS2.C; MS.ESS2.D

Title: HS-ESS2 Earth’s Systems

Performance Expectation: Develop a model based on evidence of Earth’s interior to describe the cycling of matter by thermal convection. [Clarification Statement: Emphasis is on both a one-dimensional model of Earth, with radial layers determined by density, and a three-dimensional model, which is controlled by mantle convection and the resulting plate tectonics. Examples of evidence include maps of Earth’s three-dimensional structure obtained from seismic waves, records of the rate of change of Earth’s magnetic field (as constraints on convection in the outer core), and identification of the composition of Earth’s layers from high-pressure laboratory experiments.]

Disciplinary Core Idea(s):
ESS2.A: Earth Materials and Systems Evidence from deep probes and seismic waves, reconstructions of historical changes in Earth’s surface and its magnetic field, and an understanding of physical and chemical processes lead to a model of Earth with a hot but solid inner core, a liquid outer core, a solid mantle and crust. Motions of the mantle and its plates occur primarily through thermal convection, which involves the cycling of matter due to the outward flow of energy from Earth’s interior and gravitational movement of denser materials toward the interior. ESS2.B: Plate Tectonics and Large-Scale System Interactions The radioactive decay of unstable isotopes continually generates new energy within Earth’s crust and mantle, providing the primary source of the heat that drives mantle convection. Plate tectonics can be viewed as the surface expression of mantle convection. PS4.A: Wave Properties Geologists use seismic waves and their reflection at interfaces between layers to probe structures deep in the planet. (secondary to HS-ESS2-3)

Science & Engineering Practices: Developing and Using Models Develop a model based on evidence to illustrate the relationships between systems or between components of a system. Connections to Nature of Science: Scientific Knowledge is Based on Empirical Evidence Science knowledge is based on empirical evidence. Science disciplines share common rules of evidence used to evaluate explanations about natural systems. Science includes the process of coordinating patterns of evidence with current theory.

Crosscutting Concepts: Energy and Matter Energy drives the cycling of matter within and between systems. Connections to Engineering, Technology, and Applications of Science: Interdependence of Science, Engineering, and Technology Science and engineering complement each other in the cycle known as research and development (R&D). Many R&D projects may involve scientists, engineers, and others with wide ranges of expertise.

California Environmental Principles and Concepts:
Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. SL.11-12.5: Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest. Mathematics MP.2: Reason abstractly and quantitatively. MP.4: Model with mathematics. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS2.B; HS.PS3.B; HS.PS3.D; Articulation across grade-bands: MS.PS1.A; MS.PS1.B; MS.PS2.B; MS.PS3.A; MS.PS3.B; MS.ESS2.A; MS.ESS2.B

Title: HS-ESS2 Earth’s Systems

Performance Expectation: Construct an argument based on evidence about the simultaneous coevolution of Earth’s systems and life on Earth. [Clarification Statement: Emphasis is on the dynamic causes, effects, and feedbacks between the biosphere and Earth’s other systems, whereby geoscience factors control the evolution of life, which in turn continuously alters Earth’s surface. Examples include how photosynthetic life altered the atmosphere through the production of oxygen, which in turn increased weathering rates and allowed for the evolution of animal life; how microbial life on land increased the formation of soil, which in turn allowed for the evolution of land plants; or how the evolution of corals created reefs that altered patterns of erosion and deposition along coastlines and provided habitats for the evolution of new life forms.] [Assessment Boundary: Assessment does not include a comprehensive understanding of the mechanisms of how the biosphere interacts with all of Earth’s other systems.]

Disciplinary Core Idea(s):
ESS2.D: Weather and Climate Gradual atmospheric changes were due to plants and other organisms that captured carbon dioxide and released oxygen. ESS2.E: Biogeology The many dynamic and delicate feedbacks between the biosphere and other Earth systems cause a continual co-evolution of Earth’s surface and the life that exists on it.

Science & Engineering Practices: Engaging in Argument from Evidence Construct an oral and written argument or counter-arguments based on data and evidence.

Crosscutting Concepts: Stability and Change Much of science deals with constructing explanations of how things change and how they remain stable.

California Environmental Principles and Concepts:
Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy WHST.9-12.1.a-e: Write arguments focused on discipline-specific content.

DCI Connections:
Connections to other DCIs in this grade-band: HS.LS2.A; HS.LS2.C; HS.LS4.A; HS.LS4.B; HS.LS4.C; HS.LS4.D Articulation across grade-bands: MS.LS2.A; MS.LS2.C; MS.LS4.A; MS.LS4.B; MS.LS4.C; MS.ESS1.C; MS.ESS2.A; MS.ESS2.C; MS.ESS3.C

Title: HS-ESS3 Earth and Human Activity

Performance Expectation: Construct an explanation based on evidence for how the availability of natural resources, occurrence of natural hazards, and changes in climate have influenced human activity. [Clarification Statement: Examples of key natural resources include access to fresh water (such as rivers, lakes, and groundwater), regions of fertile soils such as river deltas, and high concentrations of minerals and fossil fuels. Examples of natural hazards can be from interior processes (such as volcanic eruptions and earthquakes), surface processes (such as tsunamis, mass wasting and soil erosion), and severe weather (such as hurricanes, floods, and droughts). Examples of the results of changes in climate that can affect populations or drive mass migrations include changes to sea level, regional patterns of temperature and precipitation, and the types of crops and livestock that can be raised.]

Disciplinary Core Idea(s):
ESS3.A: Natural Resources Resource availability has guided the development of human society. ESS3.B: Natural Hazards Natural hazards and other geologic events have shaped the course of human history; [they] have significantly altered the sizes of human populations and have driven human migrations.

Science & Engineering Practices: Constructing Explanations and Designing Solutions Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

Crosscutting Concepts: Cause and Effect Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects. Connections to Engineering, Technology, and Applications of Science: Influence of Engineering, Technology, and Science on Society and the Natural World Modern civilization depends on major technological systems.

California Environmental Principles and Concepts:
Principle I The continuation and health of individual human lives and of human communities and societies depend on the health of the natural systems that provide essential goods and ecosystem services. Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both. Principle V Decisions affecting resources and natural systems are based on a wide range of considerations and decision-making processes.

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. WHST.9-10.2.a-f: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes. WHST.11-12.2.a-e: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes. Mathematics MP.2: Reason abstractly and quantitatively. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: N/A Articulation across grade-bands: MS.LS2.A; MS.LS4.D; MS.ESS2.A; MS.ESS3.A; MS.ESS3.B

Title: HS-ESS3 Earth and Human Activity

Performance Expectation: Evaluate competing design solutions for developing, managing, and utilizing energy and mineral resources based on cost-benefit ratios.* [Clarification Statement: Emphasis is on the conservation, recycling, and reuse of resources (such as minerals and metals) where possible, and on minimizing impacts where it is not. Examples include developing best practices for agricultural soil use, mining (for coal, tar sands, and oil shales), and pumping (for petroleum and natural gas). Science knowledge indicates what can happen in natural systems—not what should happen.]

Disciplinary Core Idea(s):
ESS3.A: Natural Resources All forms of energy production and other resource extraction have associated economic, social, environmental, and geopolitical costs and risks as well as benefits. New technologies and social regulations can change the balance of these factors. ETS1.B: Developing Possible Solutions When evaluating solutions, it is important to take into account a range of constraints, including cost, safety, reliability, and aesthetics, and to consider social, cultural, and environmental impacts. (secondary to HS-ESS3-2)

Science & Engineering Practices: Engaging in Argument from Evidence Evaluate competing design solutions to a real-world problem based on scientific ideas and principles, empirical evidence, and logical arguments regarding relevant factors (e.g. economic, societal, environmental, ethical considerations).

Crosscutting Concepts: Connections to Engineering, Technology, and Applications of Science: Influence of Engineering, Technology, and Science on Society and the Natural World Engineers continuously modify these technological systems by applying scientific knowledge and Engineering, Technology, and Applications of Science practices to increase benefits while decreasing costs and risks. Analysis of costs and benefits is a critical aspect of decisions about technology. Connections to Nature of Science: Science Addresses Questions About the Natural and Material World Science and technology may raise ethical issues for which science, by itself, does not provide answers and solutions. Science knowledge indicates what can happen in natural systems—not what should happen. The latter involves ethics, values, and human decisions about the use of knowledge. Many decisions are not made using science alone, but rely on social and cultural contexts to resolve issues.

California Environmental Principles and Concepts:
Principle I The continuation and health of individual human lives and of human communities and societies depend on the health of the natural systems that provide essential goods and ecosystem services. Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both. Principle V Decisions affecting resources and natural systems are based on a wide range of considerations and decision-making processes.

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.11-12.8: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. Mathematics MP.2: Reason abstractly and quantitatively.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS3.B; HS.PS3.D; HS.LS2.A; HS.LS2.B; HS.LS4.D; HS.ESS2.A Articulation across grade-bands: MS.PS3.D; MS.LS2.A; MS.LS2.B; MS.LS4.D; MS.ESS3.A; MS.ESS3.C

Title: HS-LS1 From Molecules to Organisms: Structures and Processes

Performance Expectation: Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy. [Clarification Statement: Emphasis is on illustrating inputs and outputs of matter and the transfer and transformation of energy in photosynthesis by plants and other photosynthesizing organisms. Examples of models could include diagrams, chemical equations, and conceptual models.] [Assessment Boundary: Assessment does not include specific biochemical steps.]

Disciplinary Core Idea(s):
LS1.C: Organization for Matter and Energy Flow in Organisms The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.

Science & Engineering Practices: Developing and Using Models Use a model based on evidence to illustrate the relationships between systems or between components of a system.

Crosscutting Concepts: Energy and Matter Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy SL.11-12.5: Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS1.B; HS.PS3.B Articulation across grade-bands: MS.PS1.B; MS.PS3.D; MS.LS1.C; MS.LS2.B