Modern life is impossible without traveling. The fastest way of traveling is by air. With a modern airliner （客机） you can travel in one day to places which it took a month or more to get to a hundred years ago.
Traveling by train is slower than by air, but it has its advantages （便利）.  You can see the country you are traveling through. Modern trains have comfortable seats and dining cars. They make even the longest journey enjoyable.
Some people prefer to travel by sea when possible. There are large liners and river boats. You can visit many other countries and different places. Traveling by sea is a very pleasant way to spend a holiday.
Many people like to travel by car. You can make your own timetable（时间表）。 You can travel three or four hundredmiles or only fifty or one hundred miles a day, just as you like. You can stop wherever you wish where there is something interesting to see, at a good restaurant where you can enjoy a good meal, or at a hotel to spend the night. That is why traveling by car is a popular pleasure trips, while people usually take a train or a plane when they are traveling on business.
From the passage we know the fastest way traveling is       .

A．by car

B．by train

C．by air

D．by sea

If we travel by car, we can      .

A．make the longest journey enjoyable

B．make our own timetable

C．travel to a very far place in several minutes

D．travel only fifty or one hundred miles a day

The underlined word “They” in the passage refers to (指……而言)      。

A．modern trains in the country

B．the travelers on the modern trains

C．comfortable seats and dining cars

D．the slower ways of traveling