Great changes have taken place in that school. It is no longer  it was 20 years ago,     it was so poorly equipped.

Before a problem can be solved, it must be obvious ______the problem itself is.

Well, it’s up to you, Aunt Ellen, _____ you stay or go.

       is surprising to us is that Tom can speak English fluently as though he were a native speaker.

Evidence has been found through years of study______children’s early sleeping problems are likely to continue when they grow up. 

She never laughed, _______ lose her temper.

Not until the bus disappeared in the distance ________ her school bag was gone.

We students should treasure the short senior school’s study life of three years. Once ________, the opportunity can’t get back.

—Have you ever been to Shanghai Expo Garden?
—No.It is the first time that I________to China.

Have you seen Jack recently？I wonder________with his classmates.