The teachers were always trying to the excited students at that time.A. calm down B. set

问题补充：

The teachers were always trying to the excited students at that time.

A. calm down

B. set down

C. let down

D. turn down

答案：

(答案→)A. calm down

B. set down

C. let down

D. turn down

解析：考查词组：A. calm down冷静下来，B. set down记下，C. let down让…失望，D. turn down拒绝，句意：在那个时候，老师总是想把兴奋的学生冷静下来。选A。