We must stop polluting the water.(划线部分提问)__must we stop____?划线部分是polluting the water

问题描述:

We must stop polluting the water.(划线部分提问)__must we stop____?划线部分是polluting the water
We must stop polluting the water.(划线部分提问)
____must we stop____?划线部分是polluting the water

polluting the water 是件事,可用what 代替
stop 后加 doing 表停止做某事
所以

what must we stop doing?