每日一练：职称英语考试卫生类每日一练(2018/12/28)
【单选题】
Thousands of people around theglobe step outside to gaze at their night sky. On a clear night, with noclouds, moonlight, or artificial lights to block the view, people can see morethan 14,000 stars in the sky, says Dennis Ward, an astronomer with the UniversityCorporation for Atmospheric Research (UCAR) in Boulder, Colo1. But when peopleare 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 agreat distance, you’ve witnessed light pollution. Itoccurs when light from streetlights, office buildings, signs, and other sourcesstreams into space and illuminates the night sky. This haze of light makes manystars invisible to people on Earth. Even at night, big cities like New Yorkglow from light pollution, making stargazing2 difficult.
Dust and particles ofpollution 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 greaterscale. "
Hazy skies also make it farmore difficult for astronomers to do their jobs.
Cities are getting larger.Suburbs are growing in once dark, rural areas. Light from all this newdevelopment 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 gooff course3. There’s increasing evidence, for example,that migrating birds use sunsets and sunrises to help find their way, saysSydney Gauthreaux Jr., a scientist at Clemson University in South Carolina."When light occurs at night," he says, "it has a very disruptiveinfluence. " Sometimes birds fly into lighted towers, high-rises, andcables from radio and television towers. Experts estimate that millions ofbirds die this way every year.
1.When can people see 14,000stars
A.When they have a fairly goodtelescope.
B.When they are in a largecity.
C.When the night sky is clearof clouds, moonlight and artificial lights.
D.When the night sky iswithout haze and fog.
2.Which of the followingstatements is NOT related to light pollution
A.A haze of light is formedfrom artificial lights such as streetlights and building lights.
B.Lights from differentsources stream into space and illuminate the night sky.
C.The night sky is illuminatedby the lights from big glowing cities in the night.
D.Stargazing becomes difficultbecause there is a layer of haze in the air
3.Why does the writer thinkgrowing cities affect astronomers’ work
A.Because the once dark ruralareas are polluted by lights.
B.Because they can still seestars in rural areas.
C.Because rural areas are nota good place for astronomers to study stars.
D.Because faint light givenoff by stars can still be seen on a clear night
4.Which of the following isNOT correct
A.Animals may go off coursedue to the attraction of artificial lights.
B.Animals might be attractedby artificial lights to go into cities.
C.Artificial lights at nightmay make migrating birds lose their way.
D.Attracted by artificiallights, birds fly into lighted buildings.
5.Which of the following isclosest in meaning to the title "Light Night, Dark Stars"
A.The night sky is lightcolored and stars are black.
B.Lights appear at night andstars are seen in the dark.
C.City lights illuminate thenight sky and make stars invisible.
D.City lights at nightilluminate stars in the sky.
在下面提交答题后即可查看答案与试题解析
发布评论 查看全部评论