Puzzle

 PUZZLES 

1. _ _ _ _ _.

 It is a five lettered word.If you don't remove   any letter,it refers to a grain.

 If you remove the first letter,it refers to a   source of energy.

 If you remove the second letter,it refers to   an action or an action word.

 If you remove the third letter,it refers to a   prepositional word .

 Find that word?

                      Ans: Wheat