there have been a lot of laws controlling the pollution为什么用cotrolling

分类: 作业答案 • 2022-01-09 18:02:09

问题描述：

答

there be + 名词 + 动词-ing句型,这里controlling与laws的关心是主动的,-ing表示主动.
例如：
There is a boy lying under the tree.