ecial thanks go to thousands of volunteers,without ________tireless work, none of this would be possible．

He ____ a lot of time ____ his homeworkevery day.

Take your umbrella just ________ it rains

_______ you want me to fire you, I suggest you not wear sports clothes in the office next time

Thanks to the measures ______ by the local government , the polluted river is becoming clearer andclearer and fish have begun to show up in it[ ]