71. When will you be through with your work, John?
点睛
本句中，be through (with sb./sth.)意为“已结束”。本句相当于When will you finish your work?
考点归纳
与through有关的短语还有：through and through（完全，彻底），get through（接通），see through（看完）等。through本身的含义包括：
“穿过；贯穿”。如：
You can see the three people through the mist. 透过薄雾，你能看见那三个人。
“自始至终”。如：
He will not live through tonight. 他活不过今晚了。
“因为，凭借”。如：
It was through you that we were able to meet again. 全仗你的帮助，我们才能重聚。
