问题
选择题
Scientists are convinced _____the positive effect of laughter _____physical and mental health.
A.of ;at
B.by; in
C.of ; on
D.on ;at
答案
答案:C
考查介词。be convinced of相信,名词effect后接on,故选C。
Scientists are convinced _____the positive effect of laughter _____physical and mental health.
A.of ;at
B.by; in
C.of ; on
D.on ;at
答案:C
考查介词。be convinced of相信,名词effect后接on,故选C。