1.如果到处都太拥挤，旅行会令人很不愉快。

2.如果你那时没有及时离开，我无法想象会发生什么情况。

3.如果我是他，我就会尽更大的努力按时完成任务。

1.Travel will be awful if everywhere is crowded.

2.I can’t imagine what would happen if you didn‘t leave in time.

3.Were I he, I would do my best to fulfill the task on time.