join up 联合起来，联结起来；入伍 You need to join up these two lines. 你需要把这两条线连接起来。 The railway joined up the two big cities. 铁路把两座大城连接了起来。 We'll join up with the other groups later. 我们以后再与其他小组会合。 He joined up at seventeen [in1974]. 他是17岁时[1974年]参军的。 He joined up to fight for his motherland. 他参军为祖国而战。
