1. answer the door 和open the door 有何区别：open the door 表示一般意义的“开门”，与“关门”（即close the door）相对；而answer the door 指听到门铃响或敲门声而去开门。如：

He opened the door and went out.

Will you answer the door? There’s someone knocking.

2. show sb the door 与 show sb to the door 的区别：前者意为“指着门要某人出去”，即表达“把某人撵走”或“下逐客令”的意思；后者意为送某人到门口，即相当于汉语中的送客。如：

After a long argument he showed me the door.

Mr Brown is leaving now. Will you show him to the door?

注：show sb to the door 也可说成 see sb to the door，如：

Goodbye, Mr Carter. My secretary will see you to the door.