根据句意，用所给单词的适当形式填空。
小题1:How happy we were to see the safe ____________ (arrive) of all the Chinese fishermen!
小题2:The ____________ (two) Summer Youth Olympic Games will be held in Nanjing in August,2014.
小题3:Compared with the young，People in the old days were living more ____________ (comfortable)
小题4:The ____________ (strict) his teacher is with him, the more progress he will make.
小题5:Children under 12 can’t be left at home by ___________ (them) in some states of America.