Answer:
When the natural resources Exhausted
The answer is A
The air circulated in a clockwise direction in the northern hemisphere
A proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence. ... Most factors are held constant in a scientific experiment because you can only change one factor in an experiment so if you notice something, you'll know what caused it.
Here is a hint, mitosis is the division of cells.