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
The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals,【31】this is larg
The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals,【31】this is larg
admin
2012-01-05
8
问题
The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals,【31】this is largely because,【32】animals, we stand upright. This means that our noses are【33】to perceiving those smells which float through the air,【34】the majority of smells which stick to surfaces. In fact,【35】, we are extremely sensitive to smells,【36】we do not generally realize it. Our noses are capable of【37】human smells even when these are【38】to far below one part in one million.
Strangely, some people find that they can smell one type of flower but not another,【39】others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate【40】smell receptors in the nose. These receptors are the cells which sense smells and send【41】to the brain. However, it has been found that even people insensitive to a certain smell【42】can suddenly become sensitive to it when【43】to it often enough.
The explanation for insensitivity to smell seems to be that the brain finds it【44】to keep all smell receptors working all the time but can【45】new receptors if necessary. This may【46】explain why we are not usually sensitive to our own smells—we simply do not need to be. We are not【47】of the usual smell of our own house, but we【48】new smells when we visit someone else’s. The brain finds it best to keep smell receptors【49】for unfamiliar and emergency signals【50】the smell of smoke, which might indicate the danger of fire.
选项
A、limited
B、committed
C、dedicated
D、confined
答案
A
解析
上文提到人类嗅觉不灵敏是由于人类是直立的,本句进一步解释说明这种现象导致人的鼻子只“限于”感觉到漂浮在空气中的气味。A项最符合题意。
转载请注明原文地址:https://kaotiyun.com/show/271K777K
0
专业英语四级
相关试题推荐
Sociologistsuse"power"torefertothecapacityofpeopletocontrolorinfluencetheactionsofothers.Sociologistsstudypo
Sociologistsuse"power"torefertothecapacityofpeopletocontrolorinfluencetheactionsofothers.Sociologistsstudypo
I’dratheryou______overtheeconomyduringtheperiodofitsgreateststressanddanger.
WhichoneofthefollowingwasNOTamongtheconditionsofthemanseveralyearsago?
Myparentsused_______inSouthAmericaandIwasusedtothelongdistanceflightsbetweenChinaandSouthAmericaduringthe
Whatistherelationshipbetweenthetwospeakers?
Whatisthecasualtynumberoftheaccident?
TheCarnegieFoundationreportsaysthatmanycollegeshavetriedtobe"allthingstoallpeople".Indoingso,theyhaveincre
Asanorganizeroftheconcert,hehadbeenobligedto______himselfmorethanever,toevadetheenormousnumberofapplicatio
Asitwas,theDemocratswouldcontrolthefederalgovernment______becauseofthedivisionamongtheiropponents,
随机试题
已知某企业经营杠杆系数等于2,预计息税前利润增长10%,每股收益增长30%。下列说法正确的有【】
患儿,男,生后12天。呼吸困难,哭闹不止。X线检查如图所示,最可能的诊断为
属于快速杀菌药的是( )。
血型试剂
合同生效的要件不包括()。
下列选项中,可以提议召开有限责任公司临时股东会的有()。
某家庭预计今后20年内月收入16000元,如果其中的30%可用于支付住房抵押贷款的月还款额,年贷款利率为6%,贷款成数为70%,该家庭有偿还能力的最大购买住房价格是()元。
(2015年卷一第13题)在下列哪个情形下,国家知识产权局将重新确定申请日?
浣花溪记钟惺出成都南门,左为万里桥。西折纤秀长曲,所见如连环、如玦,如带,如规,如钩;色如鉴、如琅圩,如绿沉瓜,窈然深碧,潆回城下者,皆浣花溪委也。然必至草堂,而后浣花有专名,则以少陵浣花居
把下面的六个图形分为两类,使每一类图形都有各自的共同特征或规律,分类正确的一项是:
最新回复
(
0
)