他们此刻正在等着轮到他们上公交车 They________for their turn to ___________
问题描述：
他们此刻正在等着轮到他们上公交车 They________for their turn to ___________
答
第一个空：are waiting ,第二个空：take a bus.
答
They (are waiting) for their turn to (get on the bus).