问题
选择题
Traveling around big cities by taxi can cost a lot of money, but it's usually to take the underground train to most places.
A．amazing
B．expensive
C．convenient
D．exciting
答案
答案：C
amazing令人惊异的； expensive昂贵的；convenient方便的； exciting令人兴奋的。句意：乘出租车在大城市旅行会花许多钱，但是这通常能方便的乘地铁到大部分地方。结合语境可知选C。