All possible means . However nothing can his wife dying of lung cancer.A. has tried; sto

问题补充：

All possible means . However, nothing can his wife dying of lung cancer.

A. has tried; stop

B. have tried; keep

C. have been tried; prevent

D. has been tried; stop

答案：

A. has tried; stop

B. have tried; keep

(答案→)C. have been tried; prevent

D. has been tried; stop

解析：名词用法以及动词用法。Means方法，是一个单复数同名名词，前面有all说明本句中的means是复数，谓语动词用复数形式且应该使用被动。Prevent sb from doing sth阻止某人做某事。句意：所有可能的方法都已经被尝试过了。然而，没有什么能阻止她的妻子死于癌症。