Whentheteachercamein,hecoveredhismobilephonewithatextb...

問題詳情：

 When the teacher came in, he covered his mobile phone with a textbook and pretended _______his homework.

   A. to do                B. doing               C. to be doing         D. to have done

【回答】

C

知識點：非謂語動詞

題型：選擇題