Dogs________men'sfriendsformillions

发布时间：2020-07-09 23:35:25

Dogs ________ men's friends for millions of years．Early men ________ them for hunting．













A.were; helped












B.have been; helped











C.were; used











D.have been; used

网友回答

D
以上问题属网友观点，不代表本站立场，仅供参考！