问题
选择题
__________at the gate of the theater, Susan found the ticket for the play was left at home.
A．To arrive
B．On arriving
C．As arriving
D．While arrived
答案
B
题目分析：句意：苏珊一到剧院的门口，就发现电影票被忘在家里了。On+名词/动名词="as" soon as“一......就....”故选B。
考点：