英语六级阅读理解练习附详解:汽车系统
The computer works with an antenna (天线) that takes signals from no fewer than three or the24, global positioning system (GPS) satellites. By measuring the time required for a signal totravel between the satellites and the antenna. the car's location can be pinned down within l00meters.
The satellite signals. along with inputs on speed from a wheel-speed sensor and direction froma meter, determine the car’s position even as it moves. This information is combined with amap database. Streets, landmarks and points of interest are included.
Most systems are basically identical. The differences come in hardware-the way the computeraccepts the driver's request for directions and the way it presents the driving instructions. Onmost systems, a driver enters a desired address, motorway junction or point of interest via atouch screen or disc. But the Lexusscreen goes a step further: you can point to any spot onthe map screen and get directions to it.
BMW's system offers a set of cross hairs(瞄准器上的的十字纹)that can be moved across themap (you have several choices of map scale) to pick a point you'd like to get to. Audi's screencan be switched to TV reception.
Even the voices that recite the directions can differ, with better systems like BMW's andLexus's having awider vocabulary. The instructions are available in French. German, Spanish,Dutch and Italian, as well asEnglish. The driver can also choose parameters for determining theroute: fastest, shortest or no freeways(高速公路), for example.
现在大多数汽车制造商出售的导航电脑价值都在2000美元或以上，因此它们大多用于一些豪华车内，如凌志，宝马和奥迪，也是不足为奇的事。[1]但它是一种发展中的技术——这意味着价格最终将下降——市场看来定将扩大。
即使就当前的价格而吉，导航电脑也足以令人动心。它通过精确的转弯方向提示指引你在大多数重要城市里由此地去彼地。这些指示可以模拟清晰的真人发音，并书写在驾驶者面前的屏幕上。
该电脑通过一根天线工作。这根无线至少能够接收到24家全球定位卫星中的3家。通过计算卫星与天线之间信号传播所需的时间，汽车的位置可被确定在lOO米的误差范围之内。
[4]卫星信号，连同车速传感器提供的车速数据和定向仪提供的方向一起确定出车子的位置，哪怕它处于移动当中。这些信息同一个地图数据库相结合，街道、路标或名胜之地都被包括在该数据库之中。
[3]/[5]大多数导航系统基本都是相同的。区别之处在于硬件的不同，即电脑接受驾驶者询问方向的指令，以及它提供指示的方式不同。[2]在多数系统内，驾驶者通过触摸屏或光盘输入某个目的地地址，高速公路的交汇口，或名胜之处。但是凌志车的屏幕则更胜一筹：你能够指向屏幕地图的任何一点并获得到达该地点的指示。
根据德国宝马的系统设计，地图上有一个可以移动的瞄准十字纹(有几种地图比例供选择)。你想去哪里，就可以选定那里。而奥迪车的屏幕可以转换为电视接受器。
像宝马和凌志这样的车，其更为出色的定位系统所储存的词汇量更大，甚至其复述指令的声音也可以不同。这些指令除可以英语发音外，还可以使用法语、德语、西班牙语、荷兰语和意大利语发音。驾驶者还可以通过设置参数来决定路线，比如说最快、最短、或不走高速公路的路线。
1. We learn from the passage. that navigationcomputers______________.
A) will greatly promote sales of automobiles
B) may help solve potential traffic problems
C) are likely to be accepted by more drivers
D) will soon be viewed as a symbol of luxury
2. With a navigation computer, a driver will easily find the best route to hisdestination________.
A) by inputting the exact address
B) by indicating the location of bis car
C) by checking his computer database
D) by giving vocal orders to the computer
3. Despite their varied designs, navigation computers used incars___________________.
A) are more or leas the same price
B) provide directions in much the same way
C) work on more or less the same principles
D) receive instructions from the same satellites
4. The navigation computer functions__________________.
A) by means of a direction finder and a speed detector
B) basically on satellite signals and a map database
C) mainly through the reception of turn-by-tum directions
D) by using a screen to display satellite signals
5. The navigation systems in cars like Lexus. BMW and Audi are mentioned toshow__________.
A) the immaturity of the new technology
B) the superiority of the global positioning system
C) the cause of price fluctuations in car equipment
D) the different ways of providing guidance to the driver