Question

what do muscles do? select all that apply. they receive signals from the brain to either contract or relax. they break down toxins in the blood. they store urine before it is released from the body. they work in groups to move the bodys bones. they provide a barrier against contaminants found in the environment.

Explanation:

Muscles receive neural signals for contraction/relaxation and work in groups to move bones. Breaking down toxins is mainly the liver's job, storing urine is the bladder's function, and the skin provides a barrier against contaminants.

Answer:

They receive signals from the brain to either contract or relax.
They work in groups to move the body's bones.