LS.3.1 Understand human body systems and how they are essential for life: protection, movement, and support. 

• LS.3.1.1 Use models to infer the functions of the skeletal and muscular systems.

• LS.3.1.2 Obtain, evaluate, and communicate scien- tific information to explain why skin is necessary for protection and for the body to remain healthy. 

ESS.3.2 Understand the structures of the Earth’s surface using models.

• • ESS.3.2.1 Use models to compare Earth's saltwater and freshwater features (including oceans, seas, rivers, lakes, ponds, streams, and glaciers).

  • ESS.3.2.2 Use models to compare Earth's land features (including volcanoes, mountains, valleys, canyons, caverns, and islands).