1. Cars are responsible for most of the smog in cities, _______________ (这已经对环境造成了严重的污染).
2. Man should not exploit the natural resources _______________(以牺牲其他物种为代价).
3. How close parents are to their children______________________(有很强的影响)the character of the children.
4. In the Chinese household, grandparents and other relatives__________________(起着不可缺少的作用)in raising children.
5. He always dreams of _________________(有个机会)for him to bring into full play his potential.
参考答案：
1. which has seriously polluted the environment
2. at the cost of sacrificing/loss of other species_
3. has a strong influence on/effect on
4. play indispensable roles
5. there being a chance
