Ten minutes had been made full ____ of ____ the problem.

 The flowers don’t need too much water; you can just water them _____.

Wind is now the world’s fastest growing ________ of power.

A post office should be built in a central ______ for the sake of the convenience. 

Seeing the big crowd coming towards him, he started to run down the hill，but____   and went down on his hands and knees in the melting snow.