首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
One reaction to all the concern about tropical deforestation is a blank stare that asks the question, "Since I don’t live in the
One reaction to all the concern about tropical deforestation is a blank stare that asks the question, "Since I don’t live in the
admin
2013-01-12
65
问题
One reaction to all the concern about tropical deforestation is a blank stare that asks the question, "Since I don’t live in the tropics, what docs it have to do with me?" The answer is that your way of life, wherever you live in the world, is tied to the tropics in many ways. If you live in a house, wash your hair, eat fruit and vegetables, drink soda, or drive a car, you can be certain that you are affected by the loss of tropical forests. Biologically, we are losing the richest regions on earth when, each minute, a piece of tropical forest the size of ten city blocks vanishes. As many as five million species of plants, animals and insects, 40 to 50 percent of all living things, live there, and are being irrevocably lost faster than they can be found and described. Their loss is incalculable.
Take medicine, for example. Fewer than one percent of tropical forest plants have been examined for their chemical compounds. Nonetheless, scientists have integrated a wealth of important plants into our everyday lives. The West African calabar bean is used to treat glaucoma, while the sankerfoot plant of India yields reserpine, essential for treating hypertension. A West African vine provides the basis for strophanthus, a heart medicine. Quinine, an alkaloid derived from boiling the bark of the cinchona tree, is used to prevent and treat malaria. Derivatives from the rosy periwinkle offer a 99 percent chance of remission for victims of lymphocytic leukemia, as well as a 59 percent chance of recovery from Hodgkin’s disease. In fact, of the 3,000 plant species in the world known to contain anti-cancer properties, 2,100 are from the tropical rain forest. Then there is robber. For many uses, only natural rubber from trees will do, synthetics am not good enough. Today, over half of the world’s commercial rubber is produced in Malaysia and Indonesia, while the Amazon’s rubber industry produces much of the world’s four million tons. Adding ammonia to rubber produces latex which is used for surgical gloves, balloons, adhesives, and foam robber. Latex, plus a weak mixture of acid results in sheet rubber used for footwear and many sporting goods, laterally thousands of tropical plants are valuable for their industrial uses. Many provide fiber and canes for furniture, soundproofing and insulation. Palm oil, a product of the tropics, brings to your table margarine, cooking oil, bakery products, and candles. Palm nut oil, from the seed kernel in side the fruit, is found in soap, candles, and mayonnaise. The sap from Amazonian copaiba trees, poured straight into a fuel tank, can power a truck. At present, 20 percent of Brazil’s diesel fuel comes from this tree. An expanded use of this might reduce our dependency on irreplaceable fossil fuels.
Many scientists assert that deforestation contributes to the greenhouse effect, the heating of the earth from increased carbon dioxide in the atmosphere. As we destroy forests, we lose their ability to convert carbon dioxide into oxygen. Carbon dioxide levels could double within the next half-century, warming the earth by as much as 4.5 degrees. The result? A partial melt-down of the polar ice caps, raising sea levels as much as 24 feet. A rise of 15 feet would threaten anyone living within 35 miles of the coast. Farfetched? Perhaps, but scientists warn that by the time we realize the severe effects of tropical deforestation, it will be 20 years too late. Can tropical deforestation affect our everyday lives? We only have to look at the catalogued tropical forests and the abundance of wondrous products from which we benefit every day to know the answer. After all, the next discovery could be a cure for cancer or the common cold, or the answer to feeding the hungry, or fuelling our world for centuries to come.
It can be inferred from the article that the majority of tropical forests ______.
选项
A、contain a few valuable plants which possess curative properties
B、are of little interest to scientists involved in medical research
C、could be the source of a cure for life threatening diseases and various health problems
D、as a region produce only one percent of modem medicines
答案
C
解析
文章提到人们研究了不到百分之一的热带雨林,就发现了很多中可利用的药物成分。所以不难推测,这些热带雨林可能是治疗致命的疾病和各种健康问题的良药。
转载请注明原文地址:https://kaotiyun.com/show/cj9O777K
0
考博英语
相关试题推荐
Ifeverythinggoessmoothly,thepatientwillsoonbe______fromthehospital.
Tounderstandbettertheforcesthatcontrolhumanagingandlongevity,wehavetriedtodeterminewhetherthelongerlifespano
Aninvestigationthatis______canoccasionallyyieldnewfacts,evennotableones,buttypicallytheappearanceofsuchfacts
Investmentinthepublicsector,suchaselectricity,irrigation,quarrying,publicservicesandtransport(excludingvehicles,
Formanypeople,overeatingandoverspendingareas______toChristmasascandlesandholly.
Althoughthereareoccasionaloutbreaksofgunfire,wecanreportthattherebellionhasinthemainbeen______.
A.Studythefollowingpicturecarefullyandwriteanessayofabout250-300words.B.Youressayshouldmeettherequireme
Thereisapicturebelow.Lookatitcarefullyandwriteacompositionofabout250wordsbasedonwhatitconveys.
Hereyeswereshiningbrightlyandherfacewas______withcolour.
Youdon’thavetoinstallthisradioinyournewcar.It’san______extra.
随机试题
下列不属于宏观经济调控目标的是()。
分解作用的最终目的在于稳定和提高土壤中有机物的含量,为碎屑食物链提供物质基础。()
A.Coonlls试验B.结核菌素皮试C.挑刺试验D.特异性IgG抗体测定E.循环免疫复合物测定属于检测Ⅰ型超敏反应的试验
A.听觉适应B.听觉疲劳C.暂时性听阈位移D.永久性听阈位移E.噪声聋停止接触噪声16小时后进行测定发现语频听力下降>5dB的称
下列那个化学制剂不属于高效消毒剂
医德基本原则是()
某房地产开发公司于2008年6月受让一宗土地使用权,依据受让合同支付转让方地价款8000万元,当月办妥土地使用证并支付了相关税费。自2008年7月起至2009年6月末,该房地产开发公司使用受让土地60%(其余40%尚未使用)的面积开发建造一栋写字楼并全部销
2009年1—3月,全国完成房地产开发投资4880亿元,同比增长4.1%。其中,商品住宅完成投资3422亿元,同比增长3.2%,比1—2月提高2.4个百分点,比去年同期回落31.5个百分点。1—3月,全国房地产开发企业房屋施工面积17.87亿
下列没有“成分残缺”语病的一句是:
根据客户与外包商建立的外包关系,可以将信息技术外包划分为:市场关系型外包、中间关系型外包和伙伴关系型外包。其中市场关系型外包指_______。
最新回复
(
0
)