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
专升本
The "balance of nature" is not an empty phrase. Nature provides a population to occupy a suitable environment and cuts down surp
The "balance of nature" is not an empty phrase. Nature provides a population to occupy a suitable environment and cuts down surp
admin
2018-04-17
25
问题
The "balance of nature" is not an empty phrase. Nature provides a population to occupy a suitable environment and cuts down surplus population to fit the available food supply. One means of reducing surplus population is predators (食肉动物); others are parasites (寄生虫) and diseases. Also, population density produces nervous disorders and even drives animals to mass migrations, like the lemmings (旅鼠) of Norway who plunge into(跳人) the sea.
That predators populations increase to control other animals has long been known. Many years ago, the Hudson’s Bay Company records revealed that the fox population went up and down about a year after the rabbit population had gone up and down.
Sometimes a situation occurs in which the predators population is reduced to a level below that which nature can readily replace. On Valcour Island in Lake Champlain (New York) , a costly campaign resulted in the elimination of predatory animals only to have birds and small animals—including grouse (松鸡) and hares, popular game(猎物)—increase for four years afterward. Then lacking predator control, nature resorted to diseases to cut down these populations.
Jamaica had an example of nature’s persistence in providing animals for existing habits. Sugar planters, about 75 years ago, imported mongooses to control rats. The mongooses killed off the rats and, with plentiful food, multiplied. Rats became scarce and the mongooses ate lambs, kids, puppies(小狗) , and wildlife. Eventually, food became scarce and the mongoose’s population declined.
When predators control is not available, nature brings animal population into balance by resorting to______.
选项
A、hunters
B、diseases
C、storms and flood
D、forest fires
答案
B
解析
文章第三段的最后一句说到“Then lacking predator control, nature resorted to diseases to cut down these populations.”而且在文中的第一段已指出有三种方式:其一食肉动物,其二寄生虫,其三是疾病。这里的nature即用的是第三种方式。故选B。
转载请注明原文地址:https://kaotiyun.com/show/kaiC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Nowadaysmostpeopledecidequite【61】whatkindofworktheywoulddo.WhenIwasatschool,wehadtochoose【62】whenwewerefif
ContrarytoitsrathernegativereputationintheWest,pigsinChinesecultureareasignofkindnessandgenerosity.Pigscare
OneBritishschoolisfindingthatallowingchildrentolistentomusicoreventohavetheTVonwhilestudyingishelpingimpr
Onlyoneanimalcanwalk200mileswithoutstoppingoncetorest.Itwouldtakeapersontwodaysandtwonightstowalkthisfa
Alittleboyinvitedhismothertoattendhisschool’sfirstteacher-parentmeeting.Tothelittleboy’s【21】,shesaidshewould
Readthefollowingdialogueandtrytofillupthegapswithproperwords,phrases,orsentences.Customer:【56】,butcouldy
______amajordisasterwillgetustorealizethatwecan’tgoondestroyingtherainforestsoftheworld.
MostLondoncollegeshavealibrary,withafull-timeorpart-timelibrarian,whowillbeabletogivestudentsinformationont
Aresomepeoplebornclever,andothersbornstupid?Orisintelligencedevelopedbyourenvironmentandourexperiences?Strang
Supposeyouhaveabrickandaspongewhichareexactlythesamesize.Thebrickandthespongewilloccupythesameamountofs
随机试题
某家居建材商城2018年实际占用的土地面积为20000平方米,另外商城的车场占地500平方米,拥有房产原值28000000元,该房产评估值为40000000元。2018年底,为扩大经营规模,经批准增加土地2500平方米,扩建商城投资额预计28
在光通信系统中,PIN光/电转换二极管适用于短距离、()速率通信系统。
固定义齿与牙体缺损修复对基牙要求的主要差别在于()
人们常常自己承担感冒或者牙痛等小疾病所带来的医疗费用,而不购买此类医疗保险。这体现了风险控制机制中的( )。
知识分子也是我国工人阶级的一部分。( )
有关不告不理原则,以下说法正确的是()。
按揭:一种以银行为销售者和购买者的媒介的分期付款方式。下列属于“按揭”的是()。
《阿莱斯恩典救令》
[*]
窗体上有1个名称为Command1的命令按钮,事件过程如下:PrivateSubCommand1_Click() m=-3.6 IfSgn(m)Then n=Int(m) Else n=Abs(m) EndIf
最新回复
(
0
)