This field of scientific research remains ____.

问题描述:

This field of scientific research remains ____.
A.to be untouching B.being untouched C.to be untouched D.untouched

remain
vi.
保持,逗留,剩余,残存
看到了没?是个不及物动词,所以可以不接宾语,后面那个分词作形容词做补足语,表示被动
选D