Question

a wave is a pattern of motion that carries energy. when a wave travels through matter, the matter is called a medium.
eli is playing with a spring toy. energy from his hand is transferred to the spring toy, creating a wave. as the wave moves through the spring toy, the coils in the spring toy move back and forth.
complete the sentences.
when eli moves his hand back and forth, he transfers to the spring toy. the spring toy is the the wave travels throug medium energy

Explanation:

The first blank is filled with "energy" because the text states "Energy from his hand is transferred to the spring toy". The second blank is filled with "medium" as the text says "When a wave travels through matter, the matter is called a medium" and the spring toy is the matter (medium) through which the wave travels.

Answer:

When Eli moves his hand back and forth, he transfers energy to the spring toy. The spring toy is the medium the wave travels through.