Question

----How long does it take us to go to your hometown from here?
----It takes us      hour or more to go to my hometown by       train.

A．an; a

B．a ; an

C．an; /

D．a; /

Answer 1

C

冠词的考察 hour [au?]第一个字母h不发音，所以一小时应用an hour; by 介词，当交通工具前无修饰词时，用介词by且名词前不用冠词。