Gaddafi’s failure in Sirte _________ him the last opportunity to reestablish the government.

But someday, all the work we have done will ____; we will go to college and go on to’have a suitable job．

Our school has strict rules. Almost no one can ________ using cell-phones in class .    

Clinical evidence began to ______ suggesting that the new drugs had a wider range of useful effect than had been predicted from experiments in animals.

Our teacher has _________ some very difficult questions to ask us.