. When the teacher came in the student pretended his lessons.A. to doB. to have doneC. t

问题补充：

. When the teacher came in, the student pretended his lessons.

A. to do

B. to have done

C. to be doing

D. to be done

答案：

A. to do

B. to have done

(答案→)C. to be doing

D. to be done

解析：考查非谓语动词。句意：当老师进来时，这个学生假装正在做功课。不定式表示具体的将要进行的动作。结合语境可知不定式内容为正在进行的动作，故用进行时态的不定式，选C。