Answer:
How the Muscular and the excretory system work together. The Muscular system helps the Excretory system by moving waste through the body and protect its organs. The Excretory system helps the Muscular system by getting rid of carbon dioxide from the muscles.
Explanation:
Answer:
The results are not able to be reproduced.
Explanation:
Generally, if an experiment is done and the results/similar results can not be reproduced then it can be considered invalid.
Answer:
nuclear fusion
Explanation:
When the density and temperature at the core of the gravitationally collapsing nebula reaches values when nuclear fusion is triggered and sustained, that marks the birth of the star.
