We're going to have to set it off manually. 我们得手动启动它了。

　　They set off to get the baby back. 他们接孩子去了。

　　We set off to visit the country. 我们出发去乡下探亲。

　　We set off on a short trip to Tokyo. 我们启程前往东京做短途旅行。

　　Where has your son gone? 你儿子去哪了？

　　He set off to travel around Europe. 他去周游欧洲了。