问题
选择题
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．running; to see
B．running; seeing
C．to run; to see
D．to run; seeing
答案
答案：A
stop doing sth，停止做某事，stop to do sth停下来去做某事