16．閱讀短文，從各題所給的選項中，選擇最佳選項．
Imagine the situation．You are driving along a desert or on a mountain．Then your car breaks down．You have no idea where you are．What should we do？Well，next time take a GPS with you．It is a device（設備） which uses satellites to find the user's position．It can find your position within 20meters．A GPS cannot start your car，but at least you will know where you are．
GPS，which means Global Positioning System，is a small radio receiver．It looks like a mobile phone．You can hold it in your hand，or put it in your pocket．It is sometimes put into a watch or a telephone．We also find GPS devices in cars，planes，or boats．Some of these devices have electronic maps，so you know where you are．For example，in a city they can tell you the name of the street．
There are three parts to the Global Positioning System．The first part is the receiver．You can hold it in your hand，or have it fixed into your car，plane，etc．The second part is a group of satellites orbiting（繞） the Earth．The receiver contacts（聯(lián)絡） at least four of the satellites and calculates（計算） its position．The third part of the system is a net work of ground stations．They are all over the world．They control the satellites and make sure they are working well．
Some people think that in the future the GPS will be as common as the mobile．They are becoming cheaper and more and more accurate（精確的）．There are also new uses for the GPS．Perhaps they will become like watches．Everyone will have one and you will never be lost again．
66．According to the passage，with the help of the GPS，peopleA．
A．can't be lost in a new city
B．can't find their way in different countries
C．can learn about the culture of an unknown place
D．can find their position within 2000kilometers
67．We can learn from the passage thatA．
A．there are three parts to the GPS
B．a GPS can't be put into the watch
C．a GPS can help you start your car
D．the GPS devices are becoming more and more expensive
68．The underlined word"they"in paragraph 3means"D"．
A．receivers
B．GPS devices
C．a network of ground stations
D．satellites
69．The passage is mainly aboutB．
A．the history of the GPS
B．the introduction of the GPS
C．the shape of the GPS
D．the price of the GPS
70．what can we infer（推斷） from the passage？D
A．All GPS devices have electronic maps．
B．People all over the world use the GPS for free．
C．The receiver of the GPS contacts at least five of the satellites．
D．The GPS will become more and more common in everyday life．
分析 這篇短文中作者主要給我們講述了什么是GPS，即全球衛(wèi)星定位系統(tǒng)．作者講述了它有什么作用，它的三個組成部分，以及它未來發(fā)展的方向．
解答 66．A細節(jié)理解題．根據(jù)短文第一段It can find your position to within 20 metres．A GPS cannot start your car，but at least you will know where you are．可知衛(wèi)星定位系統(tǒng)能讓你知道自己在哪兒．故選A，不會在新城市中迷路．
67．A細節(jié)理解題．根據(jù)第三段There are three parts to the Global Positioning System．可知衛(wèi)星定位系統(tǒng)有三個部分．故選A．
68．D詞義猜測題．聯(lián)系上文The third part of the system is a network of ground stations．They are all over the world第三部分是一個地面站網絡．他們在世界各地都有，可以推斷出此處句意：他們控制這衛(wèi)星并確保他們好好工作，這第二個他們指的是衛(wèi)星．故選D．
69．B細節(jié)理解題．這篇短文主要介紹了衛(wèi)星定位系統(tǒng)的工程及工作原理．故選B，介紹衛(wèi)星定位系統(tǒng)．
70．D細節(jié)理解題．根據(jù)短文最后一段in the future the GPS will be as common as the mobile，可知衛(wèi)星定位系統(tǒng)在日常生活中會變得越來越普通．故選D．
點評 做題時要在理解好文意的基礎上，與題目有機的結合，從文章中找到相關細節(jié)性的句子與選項細細比對，進行選擇或推理判斷，選出符合文章內容的正確選項．做題注意靈活，有時可采用排除法或直選法確定出最終答案．
