【题目】Today we are going to talk about the effects of smog ______ the environment.

【题目】History is ______ a subject that lets us know something in history ,it also tells us a lot of truths.

【题目】His casual remarks led to ______ by others.

【题目】You were working too hard. You’d better keep a ________between work and relaxation.

【题目】_______form the top of the tower, the south foot of the mountain is a sea of trees

【题目】Mr．Smith is always on time for everything．How ____ it be that he was late for the important meeting?

【题目】If he ____ my advice , he wouldn’t have lost his job.

【题目】The boy was seen _______ in the examination and was punished by the teacher.

【题目】The temperature has risen to more than 20 degrees centigrade．It is quite hot _______January in Zhejiang.