______has been pointed out before, air pollution is becoming serious in cities.
A: That
B: What
C: Which
D: As
A: That
B: What
C: Which
D: As
举一反三
- Such problems（）air pollution and traffic jams becoming more and more serious in some big cities. A: like B: about C: as D: of
- ______ automobile pollution, the air quality in most major cities has been lowered. A: As a result of B: In spite of C: But for D: As for
- Generally speaking, the air pollution in cities is more serious than ______ in the country. A: ones B: one C: that D: those
- Now the pollution caused by increasing number of cars ___________ more and more serious in many cities. A: ecome B: ecame C: is becoming D: had become
- It is generally believed that the (increase) __________ air pollution has caused serious problems such as global warming.