In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze(霾) that mirrors our fear of the dark. We've grown so used to this orange haze that the original gloiy of an unlit nigh, - dark enough for the planet Venus to throw shadow on Earth, is wholly beyond our experience, beyond memory almost.

We^’ve lit up the night as if it were an unoccupied country, when nothing could be further form the truth. Among mammals alone, the number of nocturnal species is astonishing, Light is a powerful biological force, and on many species it acts as a magnet(磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being“captured”by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times righter than normal, throwing nearly every aspect of their behavior out of joint including most other creatures ,we do need darkness .Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

Living in a glare of our making ,we have cut ourselves off from our evolutionary and cultural heritage—the light of the stars and the rhythms of day and night .In a very real sense light pollution causes us to lose sight of our true place in the universe, to forget the scale of our  being, which is best measured against the dimensions of a deep night with the Milky Way—the edge of our galaxy arching overhead.

50. According to the passage, human being           .

A. prefer to live in the darkness

B. are used to living in the day light

C. were curious about the midnight world

D. had to stay at home with the light of the moon

51. What does “it”(Paragraph 1) most probably refer to?

A. The night.                     B. The moon                    C. The sky                       D. The planet

52. The writer mentions birds and frogs to        .

A. provide examples of animal protection

B. show how light pollution affects animals

C. compare the living habits of both species

D. explain why the number of certain species has declined          

53. It is implied in the last paragraph that         . 

A. light pollution dose harm to the eyesight of animals

B. light pollution has destroyed some of the world heritages

C. human beings cannot go to the outer space

D. human beings should reflect on their position in the universe

54.What might be the best title for the passage?

A. The Magic light.                                    B. The Orange Haze.

C. The Disappearing Night.                               D. The Rhythms of Nature.

D

     In 2004 ,when my daughter Becky was ten , she and my husband ,Joe, were united in their desire for a dog . As for me , I shared none of their canine lust.

     But why , they pleaded. “Because I don’t have time to take care of a dog.” But we’ll do it.” Really? You’re going to walk the dog? Feed the dog? Bathe the dog?” Yes, yes , and yes .”I don’t believe you .” We will . We promise.

     They didn’t . From day two ( everyone wanted to walk the cute puppy that first day ) , neither thought to walk the dog . While I was slow to accept that I would be the one to keep thrack of her shots , to schedule her vet appointments , to feec and clean her , Misty knew this on day one . As she looked up at the ehree new humans in her life ( small , mediurn , and large ) , she calculated ,”The medium one is the sucker in the pack .”

     Quickly , she and I developed something very similar to a Vulcan mind meld ( 心灵融合 ) . She’d look at me with those sad brown wyes of hers , beam her need , and then wait , trusting I would understand — which , strangely , I almost always did . In no time , she became my feet as I read , and splaying across my stomach as I watched television .

     Even so , part of me continued to resent walking duty . Joe and Becky had promised . Not fair , I’d balk ( 不心甘情愿地做 ) silently as she and I walked . “Not fair , ” I’ d loudly remind anyone within earshot upon our retern home .

     Then one day — January 1 , 2007 , to be exact — my huband ‘ s doctor uttered an unthinkable word : leukemia ( 白血病 ) .With that , I spent eight to ten hours a day with Joe ine the hopital , doing anything and everything I could to ease his discomfort . During those six months of hospitalizations ,Becky , 12 at the time , adjusted to other adults being in the house when she returned from