位置:首页 > 题库频道 > 学历类 > 升学考试 > 高中(高考) > 英语 > 高考英语介词和介词短语练习521

Scientists are convinced _____ the positive effect of laughter _____ physical and mental health.

发布时间:2021-07-23

A.of; at

B.by; in

C.of; on

D.on; at

试卷相关题目

返回顶部