She’s girl.A. an fifteen-years-oldB. a fifteen-year-oldC. a fifteen-years-oldD. an fiftee

问题补充：

She’s girl.

A. an fifteen-years-old

B. a fifteen-year-old

C. a fifteen-years-old

D. an fifteen-year-old

答案：

A. an fifteen-years-old

(答案→)B. a fifteen-year-old

C. a fifteen-years-old

D. an fifteen-year-old

解析：句意：她是一个15岁的女孩。这里是复合形容词，其结构是数词--名词（单数）--形容词；因为girl是可数名词的单数，所以应该用不定冠词，fifteen是以辅音开头的单词，所以应该用a,故选B。