第3部分：概括大意与完成句子(第23～30题，每题1分，共8分)
下面的短文后有2项测试任务：(1)第23—26题要求从所给的6个选项中为指定段落每段选择1个小标题；(2)第27—30题要求从所给的6个选项中为每个句子确定 一个最佳选项。
23、根据材料，完成23-31题。
     1. Traffic congestion (拥堵) affects people throughout the world. Traffic jams cause smog in dozens of cities across both the developed and developing world. In the U. S. , commuters(通勤人员) spend an average of a full working, week each year sitting in traffic jams,according to the Texas Transportation Institute. While alternative ways of getting around are available, most people still choose their cars because they are looking for convenience,comfort and privacy.
     2. The most promising technique for reducing city traffic is called congestion pricing, whereby cities charge a toll to enter certain parts of town at certain times, of day. In theory, if the toll is high enough, some drivers will cancel their trips or go by bus or train. And in practice it seems to work: Singapore, London and Stockholm have reduced traffic and pollution in city centres thanks to congestion pricing.
     3. Another way to reduce rush-hour traffic is for employers to implement flextime, which lets employees travel to and from work at off-peak traffic times to avoid the rush hour. Those who have to travel during busy times can do their part by sharing cars. Employers can als0 allow more staff to telecommute (work from home) so as to keep more cars off the road altogether.
     4. Some urban planners still believe that the best way to ease traffic congestion is to build more roads, especially roads that can take drivers around or over crowded city streets. But such techniques do not really keep cars off the road; they only accommodate more of them.
     5. Other, more forward-thinking, planners know that more and more drivers and cars are taking to the roads every day, and they are unwilling to encourage more private automobiles when public transport is so much better both for people and the environment. For this reason, the American government has decided to spend some $ 7 billion on helping to increase capacity on public-transport systems and upgrade them with more efficient technologies. But environmentalists complain that such funding is tiny compared with the $ 50 billion being spent on roads and bridges.

Paragraph 1_______
A．Paying to get in
B．Changing work practice
C．Not doing enough
D．A solution which is no solution
E．Closing city centres to traffic
F．A global problem

24、Paragraph 2_______
A．Paying to get in
B．Changing work practice
C．Not doing enough
D．A solution which is no solution
E．Closing city centres to traffic
F．A global problem

25、Paragraph 3_______
A．Paying to get in
B．Changing work practice
C．Not doing enough
D．A solution which is no solution
E．Closing city centres to traffic
F．A global problem

26、Paragraph 4_______
A．Paying to get in
B．Changing work practice
C．Not doing enough
D．A solution which is no solution
E．Closing city centres to traffic
F．A global problem

27、Most American drivers think it convenient to______
A．reduce traffic jams
B．drive around
C．go by bus
D．spend more money
E．travel regularly
F．encou rage more private cars 

28、If charged high enough, some drivers may______ to enter certain parts of town.
A．reduce traffic jams
B．drive around
C．go by bus
D．spend more money
E．travel regularly
F．encou rage more private cars 

29、Building more roads is not an effective way to_______
A．reduce traffic jams
B．drive around
C．go by bus
D．spend more money
E．travel regularly
F．encou rage more private cars 

30、The U. S. government has planned to_______ updating public-transport systems.
A．reduce traffic jams
B．drive around
C．go by bus
D．spend more money
E．travel regularly
F．encou rage more private cars