我们明天必须什么时间出发去机场？

What time do we have to ___set ___off for the airport tomorrow?

他们刚刚开始了一次环球巡航之旅。

They just ___set ___off on an around-the-world cruise.

我们5点钟出发回家。

We ___set ___off for home at 5 o'clock.