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
Light Night, Dark Stars Thousands of people around the globe step outside to gaze at their night sky. On a clear night, with
Light Night, Dark Stars Thousands of people around the globe step outside to gaze at their night sky. On a clear night, with
admin
2013-10-25
35
问题
Light Night, Dark Stars
Thousands of people around the globe step outside to gaze at their night sky. On a clear night, with no clouds, moonlight, or artificial lights to block the view, people can see more than 14, 000 stars in the sky, says Dennis Ward, an astronomer with the University Corporation for Atmospheric Research(UCAR)in Boulder, Colo. But when people are surrounded by city lights, he says, they’re lucky to see 150 stars.
If you’ve ever driven toward a big city at night and seen its glow from a great distance, you’ve witnessed light pollution. It occurs when light from streetlights, office buildings, signs, and other sources streams into space and illuminates the night sky. This haze of light makes many stars invisible to people on Earth. Even at night, big cities like New York glow from light pollution, making stargazing difficult.
Dust and particles of pollution from factories and industries worsen the effects of light pollution. "If one city has a lot more light pollution than another, " Ward says, "that city will suffer the effects of light pollution on a much greater scale. "
Hazy skies also make it far more difficult for astronomers to do their jobs.
Cities are getting larger. Suburbs are growing in once dark, rural areas. Light from all this new development is increasingly obscuring the faint light given off by distant stars. And if scientists can’t locate these objects, they can’t learn more about them.
Light pollution doesn’t only affect star visibility. It can harm wildlife too. It’s clear that artificial light can attract animals, making them go off course. There’s increasing evidence, for example, that migrating birds use sunsets and sunrises to help find their way, says Sydney Gauthreaux Jr. , a scientist at Clemson University in South Carolina. "When light occurs at night, " he says, "it has a very disruptive influence. " Sometimes birds fly into lighted towers, high-rises, and cables from radio and television towers. Experts estimate that millions of birds die this way every year.
When can people see 14, 000 stars?
选项
A、When they have a fairly good telescope.
B、When they are in a large city.
C、When the night sky is clear of clouds, moonlight and artificial lights.
D、When the night sky is without haze and fog.
答案
C
解析
题意:什么时候人们能看到14000颗星星?第一段的第二句提供了答案。在没有云.没有月光.没有人造光源的情况下。可以看见14000颗星星,故本题选C。
转载请注明原文地址:https://jikaoti.com/ti/VSgsFFFM
本试题收录于:
职称英语卫生类B级题库职称英语分类
0
职称英语卫生类B级
职称英语
相关试题推荐
Readthefollowingpassageandanswerquestions9-18.1.Peoplehavebeenpaintingpicturesforatleast30,000years.Theearli
Readthefollowingpassageandanswerquestions9-18.1.Mostyoungpeopleenjoysomeformsofphysicalactivity.Itmaybewalk
Youwillhearfivepeoplegivingtheiropinionsonchanginginlife.Forquestions9-13,choosefromthelistA~Fwhateach
Youwillhearfivepeoplegivingtheiropinionsonchanginginlife.Forquestions9-13,choosefromthelistA~Fwhateach
Youwillhearfivepeoplegivingtheiropinionsonchanginginlife.Forquestions9-13,choosefromthelistA~Fwhateach
Youwillhearfivepeopletalkingabouttheshortcoursestheyattended.Forquestions9-13,choosefromthelistA-Fwhate
Youwillhearfivepeopletalkingabouttheshortcoursestheyattended.Forquestions9-13,choosefromthelistA-Fwhate
随机试题
刺激
病变而药不变,向之寿民,今为殇子矣。寿民:殇子:
躯体运动中枢位于_______;视觉中枢位于_______。
医师开具处方时,除特殊情况外必须注明的是
A.酸B.苦C.甘D.辛E.咸属“水”的味是
A.石斛B.秫米C.牛黄D.青蒿E.蜂蜜宜先煎的药材是
某工程公司承担公路的穿山隧道工程,在施工过程中隧道发生垮塌,10名人员在作业地点被困。依据《生产安全事故信息报告和处置办法》的规定,工程公司负责人接到事故报告后,应当向安全监管部门报告的时限是()小时。
下列不属于活泼型游客的个性特征的是()。
《玩偶之家》是()的作品。[2013年真题]
Whichoneofthefollowingstatementswouldsupportersofthe"nature"theoryagreewith?Whichoneofthefollowingstatements
最新回复
(
0
)