根据下面每句句意、汉语提示及英语解释，选出空白处所缺单词的正确形式。【小题1】Martin Murray is a fifteen-year-old（15岁） boyHe use

根据下面每句句意、汉语提示及英语解释，选出空白处所缺单词的正确形式。
【小题1】Martin Murray is a fifteen-year-old （15岁） boy．He used to be a “problem child”.
【小题2】—How do you study for a test?
—I study by listening （听） to tapes．
【小题3】I’m very worried （担心）about my son’s health．
【小题4】He didn’t do well in English ,so he wanted to fifteen-year-old (make better) it．
【小题5】The big building has been here for two failed （one hundred years）．

解析：【小题1】数字-+单数名词，构成复合形容词，故填fifteen-year-old【小题2】by,介词，后加名词或动名词，故填listening【小题3】be worried about 担心···，故填 worried【小题4】根据句意，可知他想提高英语，故填improve，【小题5】one hundred years 一百年是一个世纪，两个世纪，故用复数，故填centuries

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