Question

【题目】As a ____ boy, Mozart wrote his first piece of music.
A.five years old
B.five year old
C.five-years-old
D.five-year-old

Answer 1

【答案】D
【解析】句意：当还是一个5岁的孩子时，莫扎特写了他的第一首乐曲。此处修饰名词boy，所以用形容词，AB不能用作修饰名词的成分。复合形容词的构成：数词-单数名词-形容词，所以答案是D。