The correct answer should be because they want to establish a sense of time passing by and things changing over the course of time. Each new era is influenced by the previous one so the way time passes is important because as time passes by things change and the historians monitor it and record it in a chronological order.
Endocytosis<span> is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell. </span>Exocytosis<span>describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell.</span>
The flowering plant does not wilt but stands straight up reaching toward the sunlight because its cells contains mostly... Water. The answer is Water. I hope this helps!