_____pollution is the key to ___the country a comfortable and cle_英语解答

_____pollution is the key to ___the country a comfortable and clean place to live in.
为什么两个空分别是To control;keeping而不是Controlling;keep?

人气：450 ℃　时间：2020-06-19 19:36:55

解答

1)动词不定时表目的
2)“the key to ”中的“ to ”是介词,即“the key to sth/doing”