461.I wasn't sure if he was really interested or if he _____ polite.
A.was just being
B.will just be
C.had just been
D.would just be
462.I'll go to the library as soon as I finish what I ________.
A.was doing
B.am doing
C.have done
D.had been doing
461.答案是A；考查动词的时态。句意:我不能确信他是真正感兴趣呢还是仅仅为了表示礼貌。根据上文时态的暗示，故选A。
462.答案是B;考査动词的时态。句意:我一完成眼下正在做的事情就去图书馆，主句是将来时，时间状语从句用现在时。finish与选项C的have done矛盾。
