When asked why he did so,he remained_______all the time. [ ]

What’s the population ____ the U.S.A— The U.S.A has ____ population of 297 million.

They don’t know what ___________ the problem .

In our school library there anumber of books on science and the number of them growinglarger and larger.

It was in the dining hall _______ was locatedbehind the teaching building _______ I met her for the first time