He pretended an important paper when the boss entered.
A. to read
B. to be reading
C. to have read
D. to have been reading
网友回答
A. to read
(答案→)B. to be reading
C. to have read
D. to have been reading
解析：考查不定式的用法：pretend后面可以接不定式做宾语，pretend to do假装将要做，pretend to be doing假装正在做，pretend to have done假装已经做了，句意：当老板进来的时候，他假装正在看一份重要的文件。选B。