its a strange partnership,but a very effective one: satellites and space-shuttle-carried radar are helping archeologists.how?byseeingthrough sand or through treetops to locate important archeological sites.
the traditional tools of archeologists are shovels and picks.but high technology is making the archeologists work and time far more productive.
take,for example,the second 1981 flight of the space shuttle challenger.during that mission,a powerful,experimental radar was pointed at a lifeless stretch of desert in egypt called the selima sand sheet.to everyones surprise,the radar penetrated through the sand to the harder rock beneath.on the surface,there is a little indication that africas sahara desert was never anything but a desert.when the archeologists studied the radar images,they saw what seemed to be impossible: there was sand-buried landscape that was shaped by flowing water; traces of ancient riverbeds appeared to be over nine miles wide,far wider than most sections of the present-day nile river.today,the area is one of the hottest,driest desert in the world.
archeologists dug pits along the old river banks and found clues to the past: stream-rounded pebbles,stone-age axes,broken ostrich eggshells,and the shells of land snails.the archeologists were quite pleased with these findings.for years,theyd been finding stone axes scattered through the desert,and couldnt understand why.now we know that early humans were living on the banks of old rivers,and left their beautiful tools behind.some are so sharp that you could shave with them.
more recently,landsat 4,a special earth-mapping satellite,aided in the discovery of ancient mayan ruins in mexico.landsat can,with the help of false-color imagery,see through much of the area.armed with these maps,a five-person expedition took to the air in a helicopter.
by the end of the second day,the team found a stretch of walled fields that expedition members said look like old new england fences.they just go on,non-stop,for 40 miles.later in the week,an ancient village was pinpointed,as was the lost city of oxpemul,once found in the early 1930s but quickly reclaimed by the jungle.the findings made them able to map the extent of the mayan civilization in about five days.working on foot,it would have taken at least 100 years.
练习:
1.with the help of the space-shuttle-carrieD.radar, archeologists found
A.A.new stretch of the saharA.desert.
B.traces of ancient riverbeds under the saharA.desert.
C.some traditional archeological tools in the saharA.desert.
D.A.mountain beneath the saharA.desert.
2.which of the following is true of the sand-burieD.landscape?
A.it was an olD.avenue,
B.it was an undergrounD.river.
C.it was shapeD.by flowing water.
D.it was shapeD.by the olD.nile river.
3.the stream-roundeD.pebbles anD.stone-age axes which were founD.along the ancient river banks show that
A.an early human civilization once existeD.along the olD.riverbanks.
B.ancient people didnt know how to make weapons.
C.most species of animals in saharA.have disappeared.
D.early humans were gooD.at fighting with sharp weapons.
4.they in the seconD.line of the last paragraph refers to
A.olD.new englanD.fences.
B.the stretch of walleD.fields.
C.the expedition members.
D.ancient villages.
5.which of the following best summarizes the main information of the passage?
A.high-tech helps locate many fascinating archeological sites.
B.without high-tech, the archeologists work woulD.come to A.stop
C.high-tech is has taken the place of shovels anD.picks.
D.high-tech makes the archeologists work more fruitful.
【参考答案】1.B 2.C 3.A 4.B 5.D
雅思听力考试剖析:听力题型介绍
雅思听力预约医生场景解读
雅思听力考试中的图形标签题讲解
雅思听力基础不可忽视 “听历”最重要
雅思听力备考的四个技巧
两周拿下雅思听力高分的备考方法
雅思听力单选题解析
雅思听力词汇的两种基本备考方法
如何培养雅思听力考试的好习惯?
20个雅思听力备考需知的高频短语
如何高效累积雅思听力词汇
雅思听力题目的预测技巧
雅思听力的8大经典陷阱及预测方法
探究雅思听力考试是如何出题的
雅思听力选择题如何解题?
雅思听力备考的三种状态及其应对方法
雅思听力考试的三个技巧
雅思听力训练的4个具体问题
雅思听力备考的立体复习法
雅思听力考试与国内考试的区别对比
雅思听力常用信号词分类整理
浅谈雅思听力考试中介词的妙用
雅思听力备考的总体规划
最常见的雅思听力数字应对技巧
雅思听力选择题的解题经验分享
剑桥雅思听力真题的代表题型介绍
雅思听力考试时间如何分配?
解答雅思听力考题需要高效的审题方法
雅思听力材料类型分析:对话与独白
雅思听力填空题的解题技巧讲解
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |