Sometimes they're used as drugs. The classic example might be penicillin, a compound made by a fungus and used as the first widely-available antibiotic.
A is or c is the correct answer
That its not in the cell or that its just there or that you can't find it anywhere else but in the body outside the cell....
Well, using Math to see how far the Moon is from the Earth could be hard. Also, he saw that the Moon is moving in a "circle" instead of flying off, so the Earth did have a pull on the Moon so that it didn't fly away. Newton had to use Math in order to be able to identify what it's now called gravity. There's a lot that the Moon has to offer, there were no computers back then, so there's was no calculator and everything had to be done by hand.
