(Cigarette smock) has been shown to contain numerous compounds that (are known to) cause cancer in experimental animals and (the

admin2008-10-11  64

问题 (Cigarette smock) has been shown to contain numerous compounds that (are known to) cause cancer in experimental animals and (they) appear, to be strongly (linked to) human cancer, especially cancer of the lung.

选项 A、Cigarette smock
B、are known to
C、they
D、linked

答案C改为it

解析 指代前面的单数名词cigarette smoke。
转载请注明原文地址:https://kaotiyun.com/show/Z3IO777K
0

最新回复(0)