问题补充:
Isn it time you got down tothe papers?
A. mark
B. be marked
C. being marked
D. marking
答案:
A. mark
B. be marked
C. being marked
(答案→)D. marking
解析:考查动名词:句意为:还不到你着手批改这些试卷的时候吗? get down to意为“开始做某事,开始认真注意/对待某事”,to是介词,其后接名词、代词或动名词;you与mark之间存在逻辑上的主谓关系,故应该用主动形式。选D。