问题补充：
In Chicago, a computerized system has been developed that controls(管理)traffic on the city’s 235 miles of seven expressways. Now one—a controller—can follow the movement of Chicago’s traffic by looking at a set of lights. The system uses electric sensors(感应器) that are built into each expressway, every half a mile. Several times a second, the computer receives information from each sensor and translates it into green, yellow or red lights on a map in the control room. A green light means traffic is moving forty-five miles an hour, yellow means thirty to forty-five miles an hour, and red means heavy traffic—cars standing still or moving less than thirty miles an hour.
“See that red light near Austin Avenue?”the controller asked a visitor.“That’s a repair truck fixing the road, and the traffic has to go around it.”At the Roosevelt Road entrance to the expressway, the light kept changing from green to red and back to green again.“A lot of trucks get on the expressway there,”the controller explained.“They can’t speed up as fast as cars.”The sensors show immediately where an accident or a stopped car is blocking the traffic, and a truck is sent by radio to clear the road. The system has lowered the number of accidents by 18 percent. There are now 1.4 deaths on Chicago’s expressway for each one hundred million miles traveled, while in other parts of the county there are 2.6.
Traffic experts say that the Chicago system is the “coming thing”.Systems like Chicago’s are already in use on some expressways in Los Angeles and Houston.“Chicago has taken the lead,”said New York City’s traffic director and he added,“Chicago’s a good example.”
根据短文内容，选择最佳答案，并在答题卡上按要求作答。
【小题1】The passage is mainly about on expressways in Chicago.A．the traffic control systemB．the movement of the trafficC．the electric sensorsD．the traffic lights【小题2】When the cars move under 30 miles an hour, on the map in the control room.A．the red light appearsB．the red light turns yellowC．the yellow light appearsD．the green light turns red【小题3】 According to the passage, we may learn .A．some visitors are traveling on the expresswayB．there is no heavy traffic on Chicago’s expresswaysC．the traffic on Chicago’s expressways is well managedD．the number of accidents in the US has dropped by 18%【小题4】In Paragraph 2 the underlined word “it” refers to .A．the red lightB．the truck that needs repairingC．the trafficD．the truck that is fixing the road【小题5】The writer writes the article mainly by .A．giving reasons and resultsB．giving examples and explaining themC．describing what he thinksD．asking and answering questionsA
答案：
(答案→)A
解析：【主旨大意】本文介绍了美国芝加哥用电脑系统如何管理城市的高速公路。
考查点
解题思路
【小题1】
大意理解题
根据文章大意可知这篇文章主要介绍了在芝加哥高速公路上的交通控制系统，因此选A。
【小题1】
细节理解题
根据文章第一段最后一句可知答案为A the red light appears. 。
【小题1】
大意理解题
根据第二段和第三段的大意可知在芝加哥高速公路的交通被很好的管理。因此选C。
【小题1】
理解判断题
根据上文可知此处it代替“the truck that is fixing the road”。
【小题1】
写法判断题
通读全文可知作者是通过举例子讲事实来写这篇文章的。
