情景对话：
B: And are you checking in any luggage for your flight?
A: Yeah, I have one.
B: And that one?
A: Oh, this is my carry-on.
B: Ok, go ahead and put it on the scale for me please.
A: What's the weight limit?
B: 50 pounds per luggage. You're allowed to check in two pieces.
A: Ok, looks like I'm under.

知识点讲解：

· check in
托运

· check in luggage
托运行李

I have 2 bags to check in.
我有两件行李要托运。

I need to check in 2 suitcases.
我有两件行李要托运。

Luggage/baggage
行李（不可数）

A suitcase
行李箱（可数）

A bag
包/行李（可数）

A carry-on
随身行李（可数）

Yes, I have one.
是的，我有一个。

No, I don't have any.
没有，我没有托运行李。

carry-on
随身行李，登机行李

go ahead and do something
就去做（某事）吧

Go ahead and help yourself.
就随便吃吧。

Go ahead and take it.
就拿走吧。

我们甚至可以直接说：
Go ahead.

Scale [skel]
秤

Bathroom scale
体重秤

50 pounds per bag.
每件行李50磅。

23kg per bag.
每件行李23公斤。