Itisreallycrazy

问题详情：

It is really crazy ________ Peter to let his ________ son swim alone in the river.

       A. for; 5 years old                 B. of; 5 years old

       C. for; 5-years-old               D. of; 5-year-old

【回答】

D

知识点：构词法

题型：选择题