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
2015-10-30
54
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(跳入)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“Thenlacking predator control, nature resorted todiseases 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/YyYC777K
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
Infact,therewashardlyanyactivityorsocialeventthatcouldnotbesettoMusic.Weddings,births,christening,funerals,
Infact,therewashardlyanyactivityorsocialeventthatcouldnotbesettoMusic.Weddings,births,christening,funerals,
TheotherdayIheardanAmericansaytoaChinesestudentofEnglish"YouspeakverygoodEnglish."Butthestudentanswered,"
TheNorwegianGovernmentisdoingitsbesttokeeptheoilindustryundercontrol.Anewlawlimitsexplorationtoanareasouth
Woodsmen,huntersandtrackerslearnedtofollowandreadthe【21】left,behind【22】animals,men,natureandtime.Theirabilityto
Woodsmen,huntersandtrackerslearnedtofollowandreadthe【21】left,behind【22】animals,men,natureandtime.Theirabilityto
Woodsmen,huntersandtrackerslearnedtofollowandreadthe【21】left,behind【22】animals,men,natureandtime.Theirabilityto
Forthispart,youaresupposedtowriteanoticeinEnglishin100-120wordsbasedonthefollowingsituation.Remembertowrit
Mancangoonincreasinghisnumbersatthepresentrate.Inthenext30yearsmanwillfaceaperiodofcrisis.Someexpertsbe
ThehomecomputerindustryhasbeengrowingrapidlyintheUnitedStatesinthelasttenyears.Computersusedtobelarge,expe
随机试题
简单分析归约机和数据流机的异同。
抽屉试验常常用于检查
A、造血器官B、造血C、血岛D、骨髓E、造血微环境造血器官生成各种血细胞的过程
某男性工人,在塑料厂工作。突然感觉头晕、乏力、低热,伴胸闷、呼吸困难,到医院就诊。采集病史时应注意询问其是否从事以下何种工种
色甘酸钠的平喘作用机制是
某施工单位编制的某工程网络图,如图1所示,网络进度计划原始方案各工作的持续时间和估计费用,见表2。根据图1,计算网络进度计划原始方案各工作的时间参数,确定网络进度计划原始方案的关键路线和计算工期。
AccordingtoSouthKorea’snewvisaregulations,nativespeakersofEnglishwhointendtoteachEnglishinSouthKoreawillbere
简述对事实认识错误的处理方法。
打开考生文件夹下的演示文稿yswg.pptx,按照下列要求完成对此文稿的修饰并保存。删除第三张幻灯片的全部内容,将该版式设置为“标题和内容”,标题为“用户对宽带服务的建议”,内容区插入7行2列表格,第1行的第1、2列内容分别为“建议”和“百分比”。按
Themostfrustratingperiodsofanydietaretheinevitable______,whenweightloss______ifnotstops.
最新回复
(
0
)