Most students in my class are never in the morning classes.
A. of their best
B. for their best
C. in their best
D. at their best
网友回答
A. of their best
B. for their best
C. in their best
(答案→)D. at their best
解析：固定词组。at their best处于最佳状态。句意：大部分的学生在上午的课上处于最佳状态。