Thefluisbelievedbysomescientists
来源:语文精选馆 3.17W
问题详情:
The flu is believed by some scientists ________by viruses that like to reproduce in the cells inside the human nose and throat.
A.causing B.being caused C.to have caused D.to be caused
【回答】
B
知识点:非谓语动词
题型:选择题