最新Unit 2 Smart Cars课文+翻译+练习(2)

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5 Smart cars have already been built which can monitor one's driving and the driving conditions nearby. Small radars hidden in the bumpers can scan for nearby cars. Should you make a serious driving mistake (e.g., change lanes when there is a car in your "blind spot") the computer would sound an immediate warning. 能监控行车过程以及周围行车状况的智能汽车已经建造出来。藏在保险杠里的微型雷达能对周围的汽车作扫描。如果你发生重大行车失误（如变道时有车辆你“盲点”内），计算机立即会发出警报。

6 At the MIT Media Lab, a prototype is already being built which will determine how sleepy you are as you drive, which is especially important for long-distance truck drivers. The monotonous, almost hypnotic process of staring at the center divider for long hours is a grossly underestimated, life-threatening hazard. To eliminate this, a tiny camera hidden in the dashboard can be trained on a driver's face and eyes. If the driver's eyelids close for a certain length of time and his or her driving becomes erratic, a computer in the dashboard could alert the driver.

在麻省理工学院媒介实验室，业已制造出能测知你行车时有多少睡意的样车，这对长途卡车司机意义尤其重要。一连数小时注视着中夹分道线这样一个单调、几乎能催眠的过程是被严重低估的威胁生命的重大隐患。为消除这一隐患，藏在仪表板里的一架微型相机可对准开车者的脸部及眼睛。如果司机的眼帘合上一定时间，行车变得不稳，仪表板里的计算机就会向司机发出警报。

7 Two of the most frustrating things about driving a car are getting lost and getting stuck in traffic. While the computer revolution is unlikely to cure these problems, it will have a positive impact. Sensors in your car tuned to radio signals from orbiting satellites can locate your car precisely at any moment and warn of traffic jams. We already have twenty-four Navstar satellites orbiting the earth, making up what is called the Global Positioning System. They make it possible to determine your location on the earth to within about a hundred feet. At any given time, there are several GPS satellites orbiting overhead at a distance of about 11,000 miles. Each satellite contains four "atomic clocks," which vibrate at a precise frequency, according to the laws of the quantum theory.

开车最头疼的两大麻烦是迷路和交通堵塞。虽然计算机革命不可能彻底解决这两个问题，但却会带来积极的影响。你汽车上与绕轨道运行的卫星发出的无线电信号调谐的传感器能随时精确地确定你汽车的方位，并告知交通阻塞情况。我们已经有24颗环绕地球运行的导航卫星，组成了人们所说的全球卫星定位系统。通过这些卫星我们有可能以小于100英尺的误差确定你在地球上的方位。在任何一个特定时间，总有若干颗全球定位系统的卫星在11000英里的高空绕地球运行。每颗卫星都装有4个“原子钟”，它们根据量子理论法则，以精确的频率振动。

8 As a satellite passes overhead, it sends out a radio signal that can be detected by

a receiver in a car's computer. The car's computer can then calculate how far the satellite is by measuring how long it took for the signal to arrive. Since the speed of light is well known, any delay in receiving the satellite's signal can be converted into 精品文档