________he can't understand is ________his son doesn't like the school.He is very upset about this.
The first use of atomic weapons was in 1945, and their power increased enormously ever since.
It was reported that 8 policemen were sent to the forest the missing girl.
Scientists are convinced _ the positive effect of laughterphysical and mental health.
--- Smoking is bad for your health. --- Yes, I know. But I can’t.
--- What’s wrong with Mr. Brown? --- He said he would come at nine, but he didn’tat that time.