2--You are allowed one carry-on luggage and one personal item.

1--So I can bring this roll-away suitcase on the plane?

2--Yes. That will fit in the overhead bin so it won't cost you.

1--What is a personal item?

2--Anything that will fit under the seat in front of you is a personal item.

1--Can I bring my really big suitcase on the plane?

2--No. We will have to check that in for $35.

1--That's not included in the cost of the ticket?

2--No. The first checked bag is $35 and another will be an additional $25.

1--When I was younger, everything was included in the price of the ticket.

2--Times have changed.

===================================
注解：
 
1.domestic国内的
2.suitcase行李箱
3.additional额外的

===================================
译文：

1--你能告诉我这个国内航班的行李限制是什么吗？

2--你只被允许带一个随身行李和一个个人物品。

1--那我能带这个拉杆箱上飞机吗？

2--是的。这个可以放进头顶上的箱子里，所以它不用花钱。

1--个人物品是什么？

2--任何能放在你前面的座位下面的东西都算作个人物品。

1--我可以把这个大箱子带上飞机吗？

2--不可以。我们必须要检查并收取35美元。

1--那不包括在机票里吗？

2--不包括。第一个检查过的包收35美元，其他的要再额外收25美元。

1--我年轻的时候，每件东西都包括在票价里，

2--时代变了。