问题补充:
the teacher entering the classroom, the boy pretended the text.
A. To see ; to read
B. Seen; reading
C. Seeing; to be reading
D. Seeing; to have read
答案:
A. To see ; to read
B. Seen; reading
(答案→)C. Seeing; to be reading
D. Seeing; to have read
解析:see和其逻辑主语之间是主动关系,故用现在分词作时间状语;pretend后可跟不定式的三种形式:to do (一般式),to be doing(进行式),to have done(完成式),分别表示现在、进行和完成的动作,这里表示进行,故用to be reading。