H5N1BirdFlucanresultindeathunlessleft

问题详情:

H5N1BirdFlucanresultindeathunlessleft

H5N1 Bird Flu can result in death unless left ________ in time.

A.treat                              B.to treat

C.treating                           D.treated

【回答】

D

知识点:非谓语动词

题型:选择题