I can’t see the blackboard. Can you _______ the light?

 last year , my sister tried to lose weight (减肥), but ______ putting weight back on.

Ann is a careful girl．She always checks her exercises to        there are no mistakes．

—Look at the girl! Is it Susan?    —No, it __________ be her. She has gone back to her hometown. 

—Look, there_____ many birds around here, but now we hardly see them. What a pity!—Yeah! The air pollution has caused the problem!