<題組題>[題組:第19到21題]
If you cannot live without your car, Zurich might be the last city you would like to visit. In Zurich, people are welcome, but cars are not. Over the past 20 years, this city has used smart ways __19___ . One is to keep the same total number of parking spaces. For example, if 50 new parking spaces are built in one part of the city, then 50 old spaces in other parts are taken away for other uses. So the total number does not change. Some are unhappy that there are never enough spaces. That is just what the city has in mind: If people find parking more difficult, they will drive less.
__20___ , the total number of cars in the city is counted. Over 3,500 little computers are put under Zurich roads to check the number of cars that enter the city. If the number is higher than the city can deal with, the traffic lights on the roads that enter the city will be kept red. So drivers who are traveling into Zurich have to stop and wait until there are fewer cars in the city. Now, you may wonder __21___ . The answer is simple: The city wants to make more space for its people.
19.
(A) to make traffic lighter
(B) to invite people to visit
(C) to make itself a famous city
(D) to build more parking spaces
