首页
登录
职称英语
In many parts of the world, alien species are harming the environment and ca
In many parts of the world, alien species are harming the environment and ca
游客
2024-08-19
10
管理
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. [br] Where was the zebra mussel first discovered?
选项
答案
It was first discovered in the Great Lakes of North America.
解析
文章第三段第二句提到,小型贝类最早于1986年在北美五大湖发现。由此可知本题答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3726555.html
相关试题推荐
Inmanypartsoftheworld,alienspeciesareharmingtheenvironmentandca
Inmanypartsoftheworld,alienspeciesareharmingtheenvironmentandca
Inmanypartsoftheworld,alienspeciesareharmingtheenvironmentandca
Thereisaclearlinkbetweenhumansandenvironmentalproblems.________,wherev
Whenitcomestoprotectingtheenvironment,costshouldbe________.A、impossible
Everyoneknowsaboutpollutionintheenvironment,Water,air,andlandare
Aresearchersaysleadintheenvironmentcouldbeamajorcauseofviolence
Aresearchersaysleadintheenvironmentcouldbeamajorcauseofviolence
Aresearchersaysleadintheenvironmentcouldbeamajorcauseofviolence
Aresearchersaysleadintheenvironmentcouldbeamajorcauseofviolence
随机试题
Inwinter,mostanimalshaveahardtime______anythingtoeat.A、tofindB、tofin
TherearemorethanfortyuniversitiesinBritain--nearlytwiceasmanyasi
已确诊为结核性腹膜炎患者,下述哪项处理不正确()A.治疗初期应加用肾上腺皮
风险水平类指标不包括()。A.预期损失率 B.核心负债比例 C.不良贷款迁
研究表明.如果一个动作跟随情境中一个满意的变化,在类似的情境中这个动作重复的可能
《中华人民共和国义务教育法》对各种社会力量以及个人自愿捐资助学是如何规定的?
(2021年7月真题)某交易商以无本金交割外汇远期(NDF)的方式购入6个月期的
2021年6月30日,甲公司银行存款日记账账面余额为452万元,收到银行对账单的
某中药厂组织全体员工开展安全风险分级管控体系建设工作,第二车间采用相应的风险评估
如图7-51所示的各电路能正常放大交流信号的是()。
最新回复
(
0
)