Christina wasn’t saying anything, but the professor smiled at her she had done something very clever.
A. as if
B. now that
C. while
D. though
网友回答
A. as if
B. now that
C. while
D. though
解析：考查连词;A. as if好像，B. now that既然，C. while虽然，当…时候，D. though虽然，句意：Christina没有说什么，但教授对她微笑，好像她做了聪明的事。选A。