_ she might, Sue couldn’t get the door open

We’ll have a sports meet for the next three days.________, we won’t have lessons for three days.[ ]

下列各句中，标点符号使用有误的一项是( )

He knew the problem was serious and undertook to look into it he reached the office

How about your journey to Mount Emei—-Everything was wonderful except that our car twice on the way.