Whilewewererunningontheplayground,Jacksuddenlystopped

問題詳情：

While we were running on the playground, Jack suddenly stopped _______ and lay on the ground, so we all stopped______ what was wrong with him.

A. to run； to see                           B. to run； seeing 

C. running； seeing                        D. running； to see

【回答】

D

知識點：動詞和動詞短語

題型：選擇題