根据句意，用所给单词的适当形式填空。

小题1:Is the cup used to __________ water? (drink)

小题2:Don’t keep the room _________(close) when you stay in it.

小题3:The old man looked _________ (happy) at his lovely grandson.

小题4:The audience were excited because of the film star’s ___________. (arrive)

小题5:Of all the fruits, I like mangoes        (little), so I seldom buy them.

建筑工地上的起重机在15s内可以将一块很重的水泥预制板提升到楼顶，如果用人搬运需要15min时问，起重机做功的功率是人的_________倍。