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
In many parts of the world, alien species are harming the environment and causing other problems. An alien species is a species
In many parts of the world, alien species are harming the environment and causing other problems. An alien species is a species
admin
2021-12-31
37
问题
In many parts of the world, alien species are harming the environment and causing other problems. An alien species is a species of plant or animal that has moved from its original home to a new area. Sometimes people have intentionally introduced the new species; sometimes it arrives accidentally, as a side effect of international trade. In its new location, the alien species has no natural enemies, so it can grow and multiply without limit. Over time—sometimes decades, sometimes a few years—the new species takes living space and food away from the native plants and animals. The result can mean drastic change in the natural landscape and problems for people.
The tiger mosquito is an example of an alien species. This kind of mosquito is common in Asia, but in recent years it has moved to parts of southern Europe. Scientists believe that the eggs of this insect probably arrived inside some car tires that were filled with water. In a few years, the mosquitoes multiplied and spread over large areas of Italy and other countries. Tiger mosquitoes can reproduce faster than common European mosquitoes, so they quickly replaced a large percentage of the native mosquitoes. Though they don ’ t cause serious disease in humans, tiger mosquitoes are a serious nuisance. They are far more aggressive than common European mosquitoes, and the effects of their bites are worse.
Another example of a different kind of animal that has recently moved to another continent is the zebra mussel. This small shellfish was first discovered in the Great Lakes of North America in 1986. It may have come over from Rvrssia on a cargo ship. In a very few years, zebra mussels had spread over all the Great Lakes and into many important rivers. They have grown into thick masses, covering many areas of lakes or river bottoms. They have also covered and closed up pipes of power stations and water treatment centers.
Among the many examples of alien species of mammals that have caused damage is the Indian mongoose. This animal was brought to Hawaii in the 1800s to kill rats in sugarcane fields. Since then, they have grown in numbers so that today they are a major threat to bird life on the islands. One of the mongoose’ s favorite foods, in fact, is birds’ eggs. Thus, the mongoose has caused great damage to poultry farmers in Hawaii, and it has greatly reduced the numbers of many native bird species. Many of these species, which are unique to the islands, are now at risk of extinction.
Why was the Indian mongoose brought to Hawaii in the 1800s?
选项
答案
It was brought to kill rats in sugarcane fields.
解析
文章第四段第二句提到,19世纪时印度猫鼬被带去夏威夷,用于杀死甘蔗地里的老鼠。由此可知本题答案。
转载请注明原文地址:https://kaotiyun.com/show/2EVK777K
本试题收录于:
D类竞赛(专科)题库大学生英语竞赛(NECCS)分类
0
D类竞赛(专科)
大学生英语竞赛(NECCS)
相关试题推荐
(1)The35-year-oldBeijingwomaniswatchinganadshowingagianttelevisionmadebytheChinesecompanyHaier.Astreamofint
(1)Becauseofcomputersandcabletelevision,themembersoftheaudiencewillsoonbemorethanwatchers.Theywillbeableto
Weallseeandhearaboutextraordinarypeoplearoundusandwonderwhywecan’tbemorelikethem.Sometimeswechuckthatnoti
Whales,severalspeciesofwhichfaceextinction,havebecomesubjectsofconsiderablesympathy.Thesearetherecordedvoiceso
Whales,severalspeciesofwhichfaceextinction,havebecomesubjectsofconsiderablesympathy.Thesearetherecordedvoiceso
Whales,severalspeciesofwhichfaceextinction,havebecomesubjectsofconsiderablesympathy.Thesearetherecordedvoiceso
Iamgoingtoworkinatotallynewenvironment.【T1】________.Iamusedtoworkinginquitehigh-techsortofindustrythathas
随机试题
服磺胺类药需多饮水的目的是
下列说法不正确的是()。
企业在进行现金管理时,可利用的现金浮游量是指()。
马老师是一名班主任,在管理班级时,他首先设法影响整个班集体的氛围,然后再去影响单个学生的发展,最后再通过整个班集体和教师的影响来促进学生的发展。马老师的这种班级管理模式属于()。
遗传
成功的关键,在于你能否持之以恒。
用蒸馏麦芽渣提取的酒精作为汽油的替代品进入市场,使得粮食市场和能源市场发生了前所未有的直接联系。到1995年,谷物作为酒精的价值已经超过了作为粮食的价值。西方国家已经或正在考虑用从谷物提取的酒精来替代一部分进口石油。如果上述断定为真,则对于那些已经用从谷物
诊断和改正程序中错误的工作通常称为______。
Henrywantedtheclerktosendagooddoctortohisroom.Henrywantedtoknowhowmuchitcosttogotothedoctor.
Mysuggestionisthatwe______(send)foradoctoratonce.
最新回复
(
0
)