_____________ (应当注意的是) that pollution has become one of the thorniest problems in many big cities.
举一反三
- Air pollution, together with overpopulation, _______many problems in big cities today. A: are causing B: is causing C: are caused D: is caused
- Such problems（）air pollution and traffic jams becoming more and more serious in some big cities. A: like B: about C: as D: of
- The process of urbanization has caused many problems, the major one is （） A: economy B: the growth of poverty in cities C: education D: health care
- People have to ______ noise pollution in big cities.
- Tianjin has become one of the most popular tourist cities in China.