For example using the tank can determine if one thing is pure gold and another thing has a little bit of gold but also has brass and you want to know about but the shapes need to be same the size for both objects
Answer:
They are heterotrophs.
Explanation:
Animals do not produce their food. They depend on already made food.
By a person asleep is by the DONT make noise or snore and someone awake you can usually see their light on or they are noises from the other room