Students must be strict their studies and teachers should be strict their students.
A. in, at
B. at, with
C. with , in
D. in, with
网友回答
A. in, at
B. at, with
C. with , in
(答案→)D. in, with
解析：根据语境可知此句的含义是学生必须要严格要求他们的学习，老师们也应该严格要求他们的学生。其中涉及到固定短语be strict in sth和be strict with sb的基本用法，前者表示对某事要求严格，后者表示对某人要求严格。根据选择项的提示可知选择D。