根据下列句子及所给汉语注释，写出空缺处各单词的正确形式(每空只写一词)
【小题1】 These colorful (气球)make the garden more beautiful than usual.
【小题2】Customs officers examined all (行李) at the airport.
【小题3】You should think twice,but not jump at a (结论).
【小题4】 (非洲)is the second largest continent in the world.
【小题5】They like movies so they go to the (电影院) almost twice a week.
【小题6】On hearing the story,they burst into (笑声).
【小题7】He promised that he would be back on (星期四).
【小题8】They took (拥有) of the house as their own.
【小题9】He lay on his (胃) secretly to watch insects fighting.
【小题10】To tell you the (真相),I don’t agree with you.
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，如何由（2）的结论求g（x）的最大值和最小值．