PLEASE HELP ME IS STUDY ISLAND, Ecosystems & the Cycling of Matter ( no link)

In what for do plants utilize nitrogen? why do they need nitrogen?

Which would happen if more forests were cut down? a. the nitrogen cycle would be stopped b. nitrogen would be fixed by bacteria more quickly c. the amount of co2 in the atmosphere would increase d. fossil fuels would build up in the soil c the amount of co2 in the atmosphere would increase

What material did the moon come from?