The answer is cholesterol
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.
<span>Some bacteria in the soil fix nitrogen into useful forms for plants to use them. This conversion of nitrogen helps plants grow. Without the bacteria in the soil a lot of the plants would not be able to grow.</span>