题干
He is a _____ boy, so he can't go to the park by himself.
A：six-year-old
B：six year old
C：six-years-old
D：six years old
答案(点此获取答案解析）
A
He is a _____ boy, so he can't go to the park by himself.
A：six-year-old
B：six year old
C：six-years-old
D：six years old
