Answer:Nuclear fusion
Explanation:
Which event takes place first in the stages before the birth of a star? Gravity pulls gas and dust together. A protostar forms as mass increases. Nuclear fusion begins under high pressure.
Answer
(a) is the correct option
explanation :
Hair cells are the sensory receptors of both the sound related framework. hair cells distinguish development in their environment any damage in these hair cells can bring about the lowering hearing capability, and this defect is changeless. calcium ion is an imperative part of the hair cells to adjust the intensification of the signal.
The helpful bacteria and The pH balance
They are heavier because they absorbed the water.