单选题 Our English teacher has ______ son.
A. a 8-year-old B. an 8-years-old C. a 8-years-old D. an 8-year-old

【正确答案】 D
【答案解析】数字-year-old，功能相当于形容词，其中的year要用单数，所以“一个八岁的儿子”就是an 8-year-old son。
译文：我们英语老师有一个八岁的儿子。