大气污染的主因是企业生产过程中的负外部性，这一特征表现为雾霾对居民健康等造成了严重影响，企业却不愿承担责任，结果社会成本几乎由所有社会成员共担。解决这一难题（ ）
①政府应负起管理责任，推行有效治理雾霾的公共政策
②市场要发挥决定性作用，让企业既谋求自身利益又承担社会成本
③政府要运用经济手段，对空气质量超标企业进行罚款
④企业家应增强社会责任感，建立更全面的污染物排放监控体系
| A．②③ | B．①③ | C．①② | D．②④ |
______ the help of an American teacher, we can learn real English.
| A．With | B．By |
| C．In | D．For |
There are various performances ______dancing and singing in the party.
| A．included | B．including |
| C．include | D．being included |
Having appeared in more than 50 films and _______numerous Hong Kong Film Awards, Stephen Chow has been regarded_______ Hong Kong’s King of Comedy.
| A．winning, as | B．won, as |
| C．won, with | D．winning, with |
This has reduced the amount of wasted food at some schools_____38 percent.
| A．with | B．to | C．in | D．by |
But one day I __________________ what I often tell him to do.
A. was caught not doing B. was caught not to do
C. was not caught doing C. was caught to not do