The fastest way to trabel in a city is by underguound .In many big cities,there____usually more

The fastest way to trabel in a city is by underguound .In many big cities,there____usually more
than one ynder ground line.how to travel by under gro und?here is ___in for mation to know___you travel by under ground.First ,you should choose the right line.If you don't you will have to____it and take another one .Second ,you necd some coin ____your ticket.In most of the machines which sell tickets.only coins____.不打了.就这些 求翻译