在英语中，结束通话时可以使用以下几种礼貌的表达方式：
I've really got to go, I'll get back to you when I get the office.
我真的得走了，我进办公室再打给你。
Sorry, I must end the conversation. There's someone on the other line.
抱歉，我不能再说了。有另一人在线。
I've got to hang up. My wife's waiting for me.
我得挂电话了。我老婆在等我。
I hate to say this, but I really have to leave now.
很抱歉，但是我现在必须得走了。
That's ok. Don't be sorry.
没关系。别担心。
I've got a business call that I really need to take.
我有一个公务电话，现在必须得接。
Would you excuse me for just a few seconds？
你能等我几秒钟吗？
I've got a visitor.
我有一个访客。
Nice talking to you. Bye.
很高兴和你通话。再见。
Thanks for calling. I'll call you back later.
谢谢你打来电话。我稍后会回电。
根据你与对方的关系和通话的正式程度，可以选择合适的表达方式来结束通话。一般来说，较为正式和常见的表达有“I've really got to go, I'll get back to you when I get the office.”和“Sorry, I must end the conversation. There's someone on the other line.”。如果与对方较为熟悉，也可以使用“Nice talking to you. Bye.”来简洁礼貌地结束通话。