John ___ such a thing about you. He never speaks ill of you behind your back.[ ]

A. can't have said        

B. might not have said

C. couldn't say          

D. mustn't have said

如果护士在与病人沟通过程中，发现病人不主动交谈，只是被动地回答问题，此时，护士采用哪种沟通技巧比较好：（）

A.有效的倾听

B.适当的沉默

C.集中焦点

D.开放的话题