------ What happened to you yesterday evening? Why didn’t you finish your work?------____ the lights off, we could not continue our work. As a result, we had to leave.
15.---Tom is never late for work. Why is he absent today? ---Something ________ to him.
14.It is not who is right but what is right _______ is important.
13.The doctors have told him to ____ smoking and drinking.
12.This statue was put up _________ Dr. Sun Yat-sen.
11.There is no light on--- they _______ be at home.