听力原文： Most countries in the world now welcome tourists because of the money they bring in. Many countries make great efforts to encourage tourism, and many also depend on what the yearn from it to keep their economies going.
People who like adventure will even try to visit countries where travel is difficult and costs are high. Companies regularly arrange trips through the Sahara desert, or to Himalayas for whoever enjoys such trips, but the numbers of visitors are small. Most tourists try to choose whichever places have fairly comfortable, cheap hotels, quite good food, reasonable safety, sunny weather and plenty of amusements or unusual things to see. Their choice of a place for a holiday also depends very much on when they can get away; it is not very pleasant to go to a place when it is having its worst weather.
One of the big problems of a nation wishing to attract a lot of tourists is the cost of building hotels for them. Building big hotels swallows up a lot of money, and many of the countries that 'need the tourists are poor. What they spend on building has to be borrowed produces only chains of ugly hotels wherever there are beauty spots supposed to attract tourists.
Another problem is that more and more big international companies are building hotels all over the world, so that the profits from a hotel often do not stay in the country in which it has been built.
And there is also the question of training staff, teaching them foreign languages, how to cook the kind of food that the foreign tourists expect, and so on. In many countries, special colleges and courses have been set up for this.
Crime can also be a problem. Seeing tourists who seem to be much richer than themselves, the local inhabitants are often tempted to steal from them. Sometimes tourists resist and get killed, and then other tourists refuse to come to the country.
What would happen to some countries if tourism stopped？

A. Their economies would be ruined.
B. It would keep their economies going.
C. There would be no more environmental pollution there.
D. People have no chance to travel there.