选择( )should not be allowed to go out at night.A.Twelve years olds B.Twelve-year-olds为什么不能用A?

分类: 作业答案 • 2021-12-28 10:42:14

问题描述：

选择( )should not be allowed to go out at night.
A.Twelve years olds
B.Twelve-year-olds
为什么不能用A?

答

B.!
“A.Twelve years olds ”只能用“Twelve years old”没有s