2. 考研
  3. The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, but this is l

The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, but this is l

admin2021-09-24  0
问题     The human nose is an underrated tool.   Humans are often thought to be insensitive smellers compared with animals, but this is largely because,【C1】________ animals, we stand upright. This means that our noses are limited to perceiving those smells which float through the air,【C2】________the majority of smells which stick to surfaces. In fact, though, we are extremely sensitive to smells,【C3】________we do not generally realize it. Our noses are capable of detecting human smells even when these are【C4】________ to far below one part in one million.
    Strangely, some people find that they can smell one type of flower but not another, whereas others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate【C5】________smell receptors in the nose. These receptors are the cells which sense smells and send messages to the brain. However, it has been found that even people insensitive to a certain smell【C6】________can suddenly become sensitive to it when exposed to it often enough.
    The explanation for insensitivity to smell seems to be that brain finds it【C7】________to keep all smell receptors working all the time but can create new receptors if necessary. This may【C8】________ explain why we are not usually sensitive to our own smells — we simply do not need to be. We are not aware of the usual smell of our own house, but we【C9】________new smells when we visit someone else’ s. The brain finds it best to keep smell receptors available for unfamiliar and emergency signals【C10】________ the smell of smoke, which might indicate the danger of fire.
【C6】
选项 A、at first
B、at all
C、at large
D、at times
答案A
解析 根据空格前面的．insensitive to a certain smell和空格后面的suddenly become sensitive to it，可以确定空格前后是对比的关系。空格所在句的句意是：但是研究发现，即使是________对气味不敏感的人，如果经常接触这种气味，也会突然变得对它敏感起来。由此可以确定，这句话是在描述人类噢觉对某种气味从不敏感到敏感的变化过程，应该选一个表示时间概念的词。A选项at first“起初，起先”和D选项at times“有时”都表示时间概念，但是at times不符合文章语境需要，可排除，故选A。
转载请注明原文地址:https://jikaoti.com/ti/e3yjFFFM
0

在职申硕（同等学力）英语

相关试题推荐
随机试题
最新回复(0)