适当形式填空（共5分）
小题1:He promised his father that he _______________(give) up smoking this year.
小题2:I did what I can _____________(help) my brother with his English study.
小题3:The accident suddenly_______________(happen) while the lights were changing to red.
小题4:Everyone agreed that we should stop the factories ______________(pour) the dirty water into the river.
小题5:They think you’d better not ____________(join) this club this year.