定语从句的题题饿`～⒈the thing____she wasn't sure was that she failed

定语从句的题题饿`～
⒈the thing____she wasn't sure was that she failed in this exam
A.that B.which C.about which D.in which
⒉the man____you just talked to was a friend of mine.(这里写whom吧?这句是不是就是“先行词是直接位于介词后作宾语的句子”,什么时候必须用whom啊`米搞清楚`赐教ing...)
⒊can you lend me the novel___the other day?
A.that you talked
B.you talked about it
C.which you talked with
D.you talked about
偶选了D,能不能分析下撒-