—What do you think Mr.Green is like?—Haven’t you seen through him?I have warned you again

问题补充：

—What do you think Mr.Green is like?

—Haven’t you seen through him?I have warned you again and again that men of this kind

A. is in danger

B. are in danger

C. is dangerous

D. are dangerous

答案：

A. is in danger

B. are in danger

C. is dangerous

(答案→)D. are dangerous

解析：根据句意应该表达“这种人很危险”，所以使用dangerous而不是 in danger （处在危险当中），再因men of this kind 谓语动词应和men保持一致，所以答案D。