A pure substance made up of only one type of atom is an element
I think it depends on what kind of reaction are you trying to figure out but all can be correct answer
Answer: D
Explanation:
It is a parrallel circuit so it would not matter if one of the bulbs were not to work.
So that they can rely on each other to get food.
Cells provide structure for the body. They take in nutrients and convert it to energy as well.
