Some of the core reasons are:
1) Deforestation
2) Excessive use of fossil fuels
3) Unevenness of Garbage
4) Increasing Population
5) Expansion of Urban area
Hope this helps!
64 is the answer because you would double 32 hope it helps.
Well it depend what science are u talking about.
Physic would require algebra and something about graph (Reading graph)
Biology would require graphing and simple add and subtracting
Chemistry would require graph and know how each atom react to each other. <span />
Well, rabbits would eat all of the vegetation leaving other animals without food.