The night is not what it was. Once, the earth was cast half in shadow. Then came fire, candle, and light bulb, gradually drawing back the curtain of darkness. But a brigh-ter world has its drawbacks. An estimated 30 percent of outdoor lighting——plus even someindoor lighting——is wasted. Inefficient lighting costs U. S. about $10. 4 billion a year, ac-cording to bob Gent of the International Dark-Sky Association, a nonprofit that aims tocontrol light pollution.

　　Last year, in Sydney, an estimated 2.2 million Australians switched off their lights during "Earth Hour", briefly reducing that city's energy use by more than 10 per-cent.

　　Motivated by such trends, more than two dozen cities worldwide went dim on March29 this year in an hour-long demonstration.

　　A number of groups are trying to measure light pollution and assess its effect on the environment in the hope that people will reduce their own contribution to the prob-lem. Scientists are trying to report how many stars we can see. In dark rural areas, about2,000 stars are typically visible at night, compared with "maybe five" in a bright city square——and about 5,000 in centuries past.

　　People who are working while others are star-gazing may facethe greatest risks.

　　Nighttime exposure to white light can cause the growth of tumors (腫瘤), experi-ments show. Two decades of research indicate that women who work at night shifts have unusually high rates of breast cancer.

　　21.The word "drawbacks" in the first paragraph probably means __________.

　　A.benefits

　　B.interests

　　C.effects

　　D.problems

　　答案：D

　　22.The International Dark-Sky Association is an organization that __________.

　　A.strongly opposes outdoor light services

　　B.has lost some money in energy trade

　　C.has profited from the lighting business

　　D.makes efforts to reduce light pollution

　　答案：D

　　23.On March 29 this year people in many cities around the world__________.

　　A.turned out some lights for an hour

　　B.organize some events to have some fun

　　C.held an demonstration called "Earth Hour"

　　D.joined together to compete with Australians

　　答案：A

　　24.Scientists counted the number of stars__________.

　　A.to illustrate the impact of light pollution

　　B.to compare air quality in different areas

　　C.to see how the sky has changed with time

　　D.to arouse public interest in space

　　答案：A

　　25.People who work at night __________.

　　A.lose the chance to gaze stars

　　B.have a higher risk of health problem

　　C.have less exposure to white light

　　D.are able to blame for light pollution

　　答案：B

　　People become quite illogical when they try to decide what can be eaten and what can-not be eaten.If you lived in the Mediterranean, {or instance, you would consider octopus a great delicacy.You would not be able to understand why some people find it repulsive.On the other hand, your stomach would turn at the idea of frying potatoes in animal fatthe normally accepted practice in many northern countries.The sad truth is that most of us have been brought up to eat certain foods and we stick to them all our lives.

　　No creature has received more praise and abuse than the common garden snail.Cooked in wine, snails are a great luxury in various parts of the world.There are countless people who, ever since their early years, have learned to associate snails with food.My friend,Robert, lives in a country where snails are despised.As his flat is in a large town, he has no garden of his own.For years he has been asking me to collect snails from my garden and take them to him.The idea never appealed to me very much, but one day, after a heavy shower, I happened to be walking in my garden when I noticed a huge number of snails taking a stroll on some of my prize plants.Acting on a sudden impulse, I collected several dozen, put them in a paper bag, and took them to Robert.Robert was delighted to see me and equally pleased with my little gift.I left the bag in the hall and Robert and I went into the living room where we talked for a couple of hours.I had forgotten all about the snails when Robert suddenly said that I must stay for dinner.Snails would, of course, be the main dish.I did not fancy the idea and I reluctantly followed Robert out of the room.To my surprise, we saw that there were snails everywhere: they had escaped from the paper bag and had taken complete possession of the hall! I have never been able to look at a snail since then.

　　26.The word "repulsive" in Para.1 most probably means " __________".

　　A.disgusting

　　B.pleasant

　　C.acceptable

　　D.delicious

　　答案：A

　　27.We can infer from the second paragraph that when collecting the snails, the author__________.

　　A.was glad that he could share them with his friend

　　B.was angry because they might damage his beloved plants

　　C.was excited about being able to give his friend a surprise

　　D.was depressed because it was hard to extinguish them all

　　答案：B

　　28.The author finds that snails__________.

　　A.are as delicious as octopus

　　B.are disliked in his hometown

　　C.are the most controversial food

　　D.are as popular as fried potatoes

　　答案：C

　　29.The best title of this passage might be __________.

　　A.One Man's Meat is Another Man's Poison

　　B.Foods and Cultures

　　C.Snail and Octopus

　　D.People Are Illogical in Front of Delicacies

　　答案：A

　　30.As indicated in the passage, people love different foods mainly because __________.

　　A.they live in different places

　　B.they learn to eat certain foods in their families

　　C.they have different understandings of delicacy

　　D.they are too illogical

　　答案：B