When he saw a ticket on the ground, he stopped .
A. to pick it up
B. pick it up
C. to pick up it
D. pick up it
网友回答
(答案→)A. to pick it up
B. pick it up
C. to pick up it
D. pick up it
解析：本题的含义是当他看到地上有一张票的时候，他停下来把它捡起来，stop to do sth表示停下来做某事，本题的含义是停下来捡票，pick sth up表示把某物捡起来的意思，sth为代词必须放在两者之间，故本题选A。