Rose told her father that she wanted a new bike.
A. Nine-year-old
B. Nine-years-old
C. Nine year old
D. Nine years old
网友回答
(答案→)A. Nine-year-old
B. Nine-years-old
C. Nine year old
D. Nine years old
解析：此题重点考查合成形容词的基本构成，数词+名词(+形容词)；合成形容词中的名词(year, hour, metre, month等)必须用单数形式。