问题
单项选择题
It is natural for young people to be critical of their parents （）。
A. at a time
B. between time
C. at times
D. at the time
答案
参考答案：C
解析：
at times“有时”；at a time“一次；每次”；at the time of“在……时”；不说between time，但说between times“偶尔，间或”。