完成句子（共6小题；每小题1分，满分6分）
根据句意及括号内的汉语提示完成句子。（每空一词）
小题1:After about three _________ (星期) holiday, we came back to school.
小题2: The food factories in China should realize the ___________ （重要）of food safety and produce healthy food for the Chinese people.
小题3:Now more and more people are rich enough to ______(买得起) new houses and cars.
小题4:Would you mind ______(去拿) some water for me, Li Ping?
小题5:Tomorrow is his ___________ (第四十)birthday. He plans to have a party.
小题6:___________（科学家）have tried lots of times to look for aliens from other planets in the last two centuries.
