题目内容：

用所给动词的适当形式填空。

celebrate,  happen,  peel,  discuss,  improve,  catch

1.What _____________________ if people don’t have any phones or computers?

2.He tried to run to the bus stop, at last he ________________ the bus.

3.He cut the tomato into four pieces without ____________ it.

4.It’s impossible for the students ________________ their grades without hard work.

5.Don’t talk loudly. They ________________________ something important.

6.The Greens always ______________________ Thanksgiving Day in the restaurant.