Flying over a desert area in an airplane, two scientists looked down with trained eyes at trees and bushes. After an hours flight one of the scientists wrote in his book, Look here for probable metal Scientists in another airplane, flying over a mountain region,sent a message to other scientists on the ground,Gold possible. Walking across hilly ground, four scientists reported,This ground should be searched for metals. From an airplane over a hilly wasteland a scientist sent back by radio one word,Uranium.
None of the scientists had X-ray eyes: they had no magic powers for looking down below the earths surface. They were merely putting to use one of the newest methods of location minerals in the ground---using trees and plants as signs that certain minerals may lie beneath the ground on which the trees and plants are growing.
This newest method of searching for minerals is based on the fact that minerals deep in the earth may affect the kind of bushes and trees that grow on the surface.
At Watson Bar Creek, a brook six thousand feet high in the mountains of British Columbia, Canada,a mineral search group gathered bags of tree seeds. Boxed were filled with small banches from te trees. Roots were dug and put into boxes. Each bag and box was carefully marked. In a scientific laboratory the parts of the forest trees were burned to ashes and tested .Each small part was examined to learn whether there were minerals in it.
Study of the roots , branches,and seeds showed no silver. But there were small amounts of gold in the roots and a little less gold in the branches and seeds. The seeds growing nearest to the tree trunk had more gold than those growing on the ends of the branches.
If the trees had not indicated that there was gold in the ground, the scientists would not have spent money to pay for digging into the deeper. They did dig and found more fold below. They dug deeper. They found large quantities of gold.
1.Scientists were flying over a desert or hilly wasteland or a mountain region in order to search for _____ in the ground.
a.gold
b.silver
c.metals
d.minerals
2.The study of trees,branches and roots indicates that_______.
a.there were larger amounts of gold in the branches than in the seeds.
b.there were small amounts of gold in the roots than in the branches
c.there were larger amounts of gold in the seeds growing nearest to the tree trunk than seeds growing on the ends of branches.
d.there were more gold in the branches than in the roots
3.Which is the best title ?
a.Scientists searching for metals with sepcial power
b.New methods of searching for minerals
c.Gold could be found by trees and plants
d.A new method of searching for minerals---using trees and plants
4.Which of the following is not mentioned as part of a tree that can help find minerals?
a.leaves
b.roots
c.branches
d.seeds
5.The scientists were searching for minerals by using ______.
a.X-ray
b.magic power
c.a special instrument
d.trained eyes
答案:dcdad
大人物的第一桶金 川普曾捡瓶子换钱[1]
北京快递车统一“着装”配编码
China's seriousness is our best hope
一周热词榜(11.19-25)[1]-25)
修缮白金汉宫将花费3.69亿英镑 民众请愿让王室自掏腰包
习近平文联十大、作协九大开幕式讲话要点
南京高校图书馆设“冥想区”
暖心小说《小王子》第25章
我国首次出台“产权保护”顶层设计
世界最健康的驴奶酪 每公斤售880英镑
'Uncle Haipeng' shows capability of older workers
北京金融街购物中心“黑天鹅”搬家
能给洗衣机下命令的智能联网衣服面世
CBA联赛改革第一步:CBA公司成立
忘掉自拍杆吧,可口可乐推出智能自拍瓶
国外孩子们是如何看待川普当选美国总统的?
特朗普会见媒体高层:我恨你们 CNN所有人都是骗子
《神奇动物》里都有哪些神奇的动物?
中央文献术语英译:长征篇
一张图判别你的识色能力有多强
近义词 reduce 和 decrease 的区别
国办印发“辅警”管理文件 受过刑罚人员不得担任辅警
《美国队长3:内战》电影精讲
四级备考:24个四级必背听力难词
川普vs希姨 史上最尴尬感恩节
All the cards?
Air kiss 飞吻
伊万卡·特朗普在特朗普国际酒店开业典礼上的演讲
冬天只会说
NASA重金征集'太空排泄'方案
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |