【题目】When the boss entered the room, the workers were pretending ____ hard at their machines.
A.to workB.to be workingC.to have workedD.working
在线课程【答案】B
【解析】
考查不定式的进行时。句意：当老板进来时，员工们假装正在机器上努力的工作。本题考查短语pretend to do sth假装做某事，结合句意可知“假装工作”的动作正在发生，故用不定式的进行时to be doing，故选B项。