How long does it take to fly to Shanghai?
　　乘飞机到上海需要多长时间？

　　A I suppose that to go by train is cheaper, but I don't have much time.

　　A 我想乘火车更便宜一些，但是我没有那么多的时间。

　　B Maybe you should go by air. It 'll be much quicker.

　　B 也许你应该乘飞机去。那会快很多。

　　A How long does it take to fly to Shanghai?

　　A 乘飞机到上海需要多长时间？

　　B It's only about an hour.

　　B 大约只需要一个小时。

　　A And there are many flights every day, aren't there?

　　A 每天都有很多次航班吗？

　　B Yes, but it'll be more expensive than travelling by train.

　　B 是的，但是乘飞机比坐火车要贵得多。

　　Notes 注释

　　1 If you want to ask how much time something takes, you can say: How long does it take to fly to Shanghai? / How long does it take to fly to Shanghai? ;How long does the opera last? / How long does the opera last?

　　如果你要问做某事需要多长时间，你可以说：How long does it take to fly to Shanghai? / 乘飞机到上海需要多长时间?；How long does the opera last? / 歌剧演出要多长时间?

　　2 Remember, if you only compare two things, use the comparative¹ form: it is much quicker /it is much quicker; It's more expensive than travelling by train. / It's more expensive than travelling by train.

　　记住，如果你想比较两个事物，用比较级形式：it is much quicker / 快得多; It's more expensive than travelling by train. / 比乘火车要贵得多。

　　Key phrases² and sentences
　　重要的短语和句子

　　I suppose that to go by train is cheaper, but I don't have much time.
　　我想乘火车更便宜一些，但是我没有那么多的时间。

　　Maybe you should go by air.
　　也许你应该乘飞机去。

　　It is much quicker.
　　那会快得多。

　　How long does it take to fly to Shanghai?
　　乘飞机到上海需要多长时间？

　　It's only about an hour.
　　大约只需要一个小时。

　　And there are many flights every day, aren't there?
　　每天都有很多次航班吗？

　　Yes, but it'll be more expensive than travelling by train.
　　是的，但是乘飞机比坐火车要贵得多。