How often are the Olympic Games held – fouryears.

To their great _____, Tom’s problem provednot to be as serious as they had feared.

The man went to bed，and when he woke up，he found his shoes still on．

the last three decades, the number of peopleparticipating in physical fitness programs___ sharply.

You can go out, _________you promise to be back before 11 o’clock