Tomisonly.Idon’tthinkaboyshouldbeallowedtodrive.A. fourteen-year-old;fourteen-year-oldB. f

Tom is only .
I don’t think a boy should be allowed to drive.
A. fourteen-year-old;fourteen-year-old
B. fourteenyearsold;fourteen-year-old
C. fourteenyearsold;fourteen-years-old
D. fourteen-year-old;fourteenyearsold

A. fourteen-year-old;fourteen-year-old(答案→)B. fourteenyearsold;fourteen-year-oldC. fourteenyearsold;fourteen-years-oldD. fourteen-year-old;fourteenyearsold解析：句意：汤姆只有十四岁。——我认为不应该允许一个十四岁的孩子驾车。英语中两个或多个单词中间可以用短横线连接起来，起一个相当于形容词或者名词的作用，这类单词叫做合成词。其一般构成规则就是其构成单词一般都要用原形。结合语境可知前文指的是人的年龄，不用合成词。下文指的是十四岁的孩子，选项C结构错误。故选B。

就是这个解释