搜题
网友您好，请在下方输入框内输入要搜索的题目：
搜题
题目内容 （请给出正确答案）
提问人：网友liqi8889 发布时间：2022-01-07
[主观题]

The human criterion for perfect vision is 20/20 for reading the standard lines on a Snelle

n eye chart without a hitch. The score is determined by how well you read lines of letters of different sizes from 20 feet away. But being able to read the bottom line on the eye chart does not approximate perfection as far as other species are concerned. Most birds would consider us very visually handicapped. The hawk, for instance, has such sharp eyes that it can spot a dime on the sidewalk while perched on top of the Empire State Building. It can make fine visual distinctions because it is blessed with one million cones (视锥细胞) per square millimeter in its retina (视网膜). And in water, humans are farsighted, while the kingfisher, swooping down to spear fish, can see well in both the air and water because it is endowed with two foveae(凹窝)-areas of the eye, consisting mostly of cones, that provide visual distinctions. One fovea permits the bird, while in the air, to scan the water below with one eye at a time. This is called monocular vision. Once it hits the water, the other fovea joins in, allowing the kingfisher to focus both eyes, like binoculars, on its prey at the same time. A frog's vision is distinguished by its ability to perceive things as a constant motion picture. Known as "bug detectors", a highly developed set of cells in a frog's eyes responds mainly to moving objects. So, it is said that a frog sitting in a field of dead bugs wouldn't see them as food and would starve.

The bee has a "compound" eye, which is used for navigation. It has 15,000 facets that divide what it sees into a pattern of dots, or mosaic. With this kind of vision, the bee sees the sun only as a single dot, a constant point of reference. Thus, the eye is a superb navigational instrument that constantly measures the angle of its line of flight in relation to the sun. A bee's eye also gauges flight speed. And if that is not enough to leave our 20/20 "perfect vision" paling into insignificance, the bee is capable of seeing something we can't ultraviolet light. Thus, what humans consider to be "perfect vision" is in fact rather limited when we look at other species.

However, there is still much to be said for the human eye. Of all the mammals, only humans and some primates can enjoy the pleasures of color vision.

The Snellen eye chart measures one's eyesight by ______.

A．the number of lines he reads

B．the number of letter he reads

C．the distance he stands away from the chart

D．the speed at which he recognizes the letters

简答题官方参考答案 （由简答题聘请的专业题库老师提供的解答）
查看官方参考答案
更多“The human criterion for perfect vision is 20/20 for reading the standard lines on a Snelle”相关的问题
第1题
Demography is the statistical study of human populationIt can be a-general science that ca

Demography is the statistical study of human population

It can be a-general science that can be applied to any kind

of dynamic population, that is, one that changed over 【M1】______

the time or space. It encompasses the study of the size, 【M2】______

structure and distribution of populations, and spatial or

temporal changes in them in response to birth, death,

migration and aging.

Human demography is the most well known discipline

of demography, and typically what people refer when 【M3】______

using the term demography. Demographic analysis

can be applied to whole societies or to groups defined by

criterion such as education, nationality, religion and ethnicity. 【M4】______

In academia, demography is often regarded as a branch

of either economy or sociology. Formal demography 【M5】______

limits its object of study to the measurement of populations

processes, when the more broad field of social demography 【M6】______

studies also analyze the relationships between

economic, social, cultural and biological processes influencing on 【M7】______

a population.

Ibn Khaldun (1332-1406) is regarded as the "father of demography"

for his economic analysis of social organization which

produced the first scientific and theoretical work on

population, development, and group dynamics. At the end of the

18th century, Thomas Malthus concluded that, if unchecked,

populations would be subject to exponential growth. He feared

that population growth would intend to outstrip growth in food 【M8】______

production, leading to ever increased famine and poverty; he 【M9】______

is seen as the intellectual father of ideas of overpopulation and

the limits for growth. Later more sophisticated and realistic 【M10】______

models were presented by Benjamin Gompertz and Verhulst.

【M1】

点击查看答案
第2题
One of the most popular literary figures in American literature is a woman who spent almos
t half of her long life in China, a country on a continent thousands of miles from the United States. In her lifetime she earned this country's most highly acclaimed literary award, the Pulitzer Prize, and also the most prestigious form. of literary recognition in the world, the Nobel Prize for literature.

Pearl S. Buck was almost a household word throughout much of her life time because of her prolific literary output, which consisted of some eighty-five published works, including several dozen novels, six collections of short stories, fourteen books for children, and more than a dozen works of nonfiction. When she was eighty years old, some twenty-five volumes were awaiting publication. Many of those books were set in China, the land in which she spent so much of her life. Her books and her life served as a bridge between the cultures of the East and the West. As the product of those two cultures she became, as she described herself, "mentally bifocal". Her unique background made her into an unusually interesting and versatile human being.

As we examine the life of Pearl Buck, we cannot help but be aware that we are in fact meeting three separate people, a wife and mother, an internationally famous writer, and a humanitarian and philanthropist (慈善家). One cannot really get to know Pearl Buck without learning about each of the three. Though honored in her lifetime with the William Dean Howell Medal of the American Academy of Arts and Letters in addition to the Nobel and Pulitzer prizes, Pearl Buck as a total human being, not only a famous author, is a captivating subject of study.

What is the main purpose of the passage？

A．To offer a criterion of the works of Pearl Buck.

B．To illustrate Pearl Buck's views on Chinese literature.

C．To indicate the background and diverse interests of Pearl Buck.

D．To discuss Pearl Buck's influence on the cultures of the East and the West.

点击查看答案
第3题
It has been a hundred years since the last big one in California, the 1906 San Francisco e
arth quake, which helped give (1)_____ to modem earthquake science. A century later, we have a highly successful (2)_____, called plate tectonics, that explains why 1906-type earthquakes happen—along with why continents drift, mountains rise, and volcanoes (3)_____ the Pacific Rim. Plate tectonics may be one of the (4)_____ triumphs of the human mind, geology's (5)_____ to biology's theory of evolution. And yet scientists still can't say when an earthquake will happen. They can't even come (6)_____.

What scientists can do right now is make good maps of fault zones and (7)_____ out which ones are probably due (8)_____ a rupture. And they can make forecasts. A forecast might say that, over a certain number of years, there is a certain (9)_____ of a certain magnitude earthquake in a (10)_____ spot. And that you should fix your house to its foundation and glue the water heater to the wall.

Turning forecasts into predictions—"a magnitude 7 earthquake is (11)_____ here three days from now"—may be impossible, but scientists are doing everything they can to solve the (12)_____ of earth quakes. They break rocks in laboratories, studying how stone (13)_____ under stress. They hike (14)_____ ghost forests where dead trees (15)_____ of long-ago tsunamis. They make maps of unsecured, balanced rocks to see where the ground has (16)_____ in the past and how hard. They dig ditches across faults, searching for the active trace. They have wired up fault zones with so many sensors it is (17)_____ the Earth is a patient (18)_____ intensive care.

(19)_____, we tell ourselves—trying hard to be persuasive—there must be some way to (20)_____ order and criterion on all that untrustworthy ground.

A．birth

B．rise

C．ground

D．way

点击查看答案
第4题
均值一方差标准[mean—variance criterion（M—V criterion)]

均值一方差标准[mean—variance criterion(M—V criterion)]

点击查看答案
第5题
Usually, the wear criterion for finishing is lower than that for roughing.
点击查看答案
第6题
What is the criterion of CET adopted in this course-book by Chen Hongwei and Li Yadan （）
点击查看答案
第7题
The Routh–Hurwitz criterion is a necessary and sufficient criterion for determining the stability of linear systems.
点击查看答案
第8题
效标效度（criterion validitv)

效标效度(criterion validitv)

点击查看答案
第9题
The criterion used in IC analysis is______A．transformationB．conjoiningC．groupingD．substitu

The criterion used in IC analysis is______

A．transformation

B．conjoining

C．grouping

D．substitutability

点击查看答案
第10题
Obesity is defined as body weight of 15 percent or more above the ideal for one's height a
nd age.【C1】______ this criterion, about one third of the adult population of the United States is obese. The【C2】______ of obesity vary in different races, cultures, sub-cultures, and social classes. In industrialized countries, fatness tends to be【C3】______ correlated with socioeconomic status: people in lower social classes tend to be more obese. In economically backward nations, the direction of the correlation is reversed; the richer, the fatter. The situation in the underdeveloped world probably approximates the【C4】______ of affairs through most of human evolution. Particularly for women,【C5】______ pregnancies could 【C6】______ into times of scarcity, larger internal food【C7】______ were adapted in the face of variable external reserves.

Although obesity may sound like a (n)【C8】______ phenomenon, it is to some degree【C9】______ relative. A study of black and white undergraduates yielded【C10】______ results. Even though blacks, and especially black females, were heavier than whites, they were more satisfied with their weight and less likely to find weight in other people【C11】______ Men were more concerned【C12】______the weight of their dates than women were, but black men were【C13】______ likely to refuse to date a woman because of her weight.

Contemporary North American culture is【C14】______ with thinness, particularly for women. Compared to the Rubenesque view of beauty of just a few centuries ago, the prototypes of feminine beauty【C15】______ in the mass media today look emaciated, that is, extremely thin. The standards have even changed【C16】______ since the 1950s, when the prototype was replete with large breasts and slightly protruding abdomen. A study of Playboy centerfolds found a ten percent decrease in the ratio of weight to height from the late 1950s to the late 1970s,【C17】______ by a dramatic increase in the number of articles on dieting in popular women's magazines. In【C18】______ to contemporary Western societies, some other cultures【C19】______ beauty with bulk. This most often occurs in societies in which food is scarce,【C20】______ women who are healthy and have more resources tend to be heavier and hence are seen as more attractive.

【C1】

A．With

B．In

C．By

D．Through

点击查看答案
考试指南 全部 >
2024年自考考试时间安排表 开考时间是几月 自学考试大专要考哪些科目 2024自考开考课程一览表 2024年10月自学考试专业和科目一览表 2024年10月全国各省自考专业科目一览表 自考统考时间一般是每年的几月份 2024年4月宁夏自学考试成绩查询入口 自考查成绩时间 每年自考专升本一年可以考几次 大概时间是什么时候 自考大专有哪些科目 专业科目一览表 自考大专需要什么条件与要求 需要多少钱 2024自考大专报名时间 各省具体时间一览表
重要提示： 请勿将账号共享给其他人使用，违者账号将被封禁！
查看《购买须知》>>>
重置密码
账号：
旧密码：
新密码：
确认密码：
确认修改
购买搜题卡查看答案
购买前请仔细阅读《购买须知》
请选择支付方式
微信支付
支付宝支付
点击支付即表示你同意并接受《服务协议》和《购买须知》
立即支付
搜题卡使用说明

1. 搜题次数扣减规则：

功能 扣减规则
基础费
（查看答案）		 加收费
（AI功能）
文字搜题、查看答案 1/每题 0/每次
语音搜题、查看答案 1/每题 2/每次
单题拍照识别、查看答案 1/每题 2/每次
整页拍照识别、查看答案 1/每题 5/每次

备注：网站、APP、小程序均支持文字搜题、查看答案；语音搜题、单题拍照识别、整页拍照识别仅APP、小程序支持。

2. 使用语音搜索、拍照搜索等AI功能需安装APP（或打开微信小程序）。

3. 搜题卡过期将作废，不支持退款，请在有效期内使用完毕。

找回账号密码
联系在线客服
请使用微信扫码支付(元)

订单号：

遇到问题请联系在线客服

请不要关闭本页面，支付完成后请点击【支付完成】按钮
遇到问题请联系在线客服
恭喜您，购买搜题卡成功 系统为您生成的账号密码如下：
重要提示：请勿将账号共享给其他人使用，违者账号将被封禁。
发送账号到微信 保存账号查看答案
怕账号密码记不住？建议关注微信公众号绑定微信，开通微信扫码登录功能
警告：系统检测到您的账号存在安全风险

为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！

- 微信扫码关注简答题 -
警告：系统检测到您的账号存在安全风险
抱歉，您的账号因涉嫌违反简答题购买须知被冻结。您可在“简答题”微信公众号中的“官网服务”-“账号解封申请”申请解封，或联系客服。
- 微信扫码关注简答题 -
请用微信扫码测试
欢迎分享答案

为鼓励登录用户提交答案，简答题每个月将会抽取一批参与作答的用户给予奖励，具体奖励活动请关注官方微信公众号：简答题

简答题官方微信公众号

尊敬的用户，您尚未绑定微信号
扫码关注微信公众号，将会重置密码，开通微信扫码登录功能
您可能还需要：
重置密码 查看订单 联系客服
简答题
下载APP
关注公众号
TOP