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
53
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.
If the percentage of carbon dioxide in the air continues to increase at current rates ______.
选项
A、average daily temperatures worldwide could increase considerably
B、some sea level islands could be threatened by flooding
C、all coastal regions throughout the world could be at serious risk
D、all of the above
答案
D
解析
文章提到了热带雨林减少可能带来的危害,包括气温升高,极地冰山融化,海平面升高,这些将导致海岸边35英里的地方被海水淹没。所以答案选D。
转载请注明原文地址:https://jikaoti.com/ti/2WHYFFFM
0
考博英语
相关试题推荐
Evenifitseconomycontinuestorecover,theUSisincreasinglybecominganationofp.timersandtemporaryworkers.This____
Alltheprisonerswillbe______infivemonths.
Investmentinthepublicsector,suchaselectricity,irrigation,quarrying,publicservicesandtransport(excludingvehicles,
Waterwillevaporatefromanywettedsurface.A.significantlylargefractionoftherainfallthatfallsonlandisreturnedto
Thedirectorhas______mewiththeunpleasantjobofdismissingperfectlygoodworkersthatthefirmcannolongeraffordtoemp
Thewomenworkersprotestedstronglythattheirwageswerenotin______totheworktheyhaddone.
Manyquarrelshave______throughmisunderstanding;howtosolvethemisimportant.
Despiteongoingnegotiationswithitsunions,UnitedAirlineshastoldthebankruptcycourtthatthe"likelyresult"willbead
Asthe______tothegeneralstrikethemanagementpromisedtoincreasetheworkers’payment.
Thefirstbig-namehackersincludeSteveWozniak,BillGatesandLinusTorvalds,allnowhighlyrecognisablenamesbehindmanyo
随机试题
人民法院判决第三人承担义务或者减损第三人权益的,第三人有权依法提起上诉。()
柳永《八声甘州(对潇潇暮雨洒江天)》着力抒写的思想情绪是()
典型胃溃疡疼痛的特点是
A、甲硝唑B、米索前列醇C、硫酸铝D、西咪替丁E、奥美拉唑增加黏膜保护层的厚度,减轻胃酸和消化酶的侵蚀,减轻损伤的药为( )。
对犯罪嫌疑人逮捕后的侦查羁押期限不得超过()。
( )是治安管理处罚中最常见的制裁方法。
祖父现在的年龄是小明的6倍,过几年之后,祖父的年龄将是小明的5倍,再过几年之后,祖父的年龄将是小明的4倍,请问小明今年多少岁?
已知a1=2,a2=2,且an=|an-1-an-2|,n=3,4,5,…,则a20,a21和a22的值分别是().
在VisualFoxPro中,使用LOCATEALLFOR命令按条件查找记录,可用来判断命令找到记录的逻辑条件是:
•Lookatthenotesbelow.•Someinformationismissing.•Youwillhearawomanorderingsomeelectricalequipment.•
最新回复
(
0
)