2012年英语职称考试 理工 B类 浓缩版 阅读理解 完形填空 直接打印

第八篇 A Biological Clock

Every living thing has what scientists call a biological clock that controls behavior. The biological clock tells 1 plants when to form flowers and when the flowers should open1. It tells 2 insects when to leave the protective cocoons and fly away, and it tells animals and human beings when to eat, sleep and wake.

Events outside the plant and animal 3 affect the actions of some biological clocks. Scientists recently found, for example, that a tiny animal changes the color of its fur 4 because of the number of hours of daylight. In the short 5 days of winter, its fur becomes white. The fur becomes gray brown in color in the longer hours of daylight in summer.

Inner signals control other biological clocks. German scientists found that some kind of internal clock seems to order birds to begin their long migration 6 flight twice each year.

Birds 7 prevented from flying become restless when it is time for the trip. 8 but they become calm again when the time of the flight has ended.

Scientists say they are beginning to learn which 9 part of the brain contain biological clocks. An American researcher, Martin Moorhead, said a small group of cells near the front of the brain 10 seems to control the timing of some of our actions. These 11 cells tell a person when to 12 awaken , when to sleep and when to seek food. Scientists say there probably are other biological clock cells that control other body activities. Dr. Moorhead is studying 13 how our biological clocks affect the way we do our work2. For example, most of us have great difficulty if we must often change to different work hours.

14 It can take3 many days for a human body to accept the major change in work hours. Dr. Moorhead said industrial officials should have a better understanding of biological clocks and how they affect workers. He said 15 such understanding could cut sickness and accidents at work and would help increase a factory’s production.

第九篇 Wonder Webs

Spider webs are more than homes, and they are ingenious traps. And the world’s best web spinner may be the Golden Orb Weaver spider. The female Orb Weaver spins a web of fibers thin enough to be invisible to insect prey, yet 1 tough enough to snare a flying bird without breaking. The secret of the web’s strength? A type of super-resilient 2 silk called dragline. When the female spider is ready to 3 weave the web’s spokes and frame, she uses her legs to draw the airy thread out through a hollow nozzle in her belly. Dragline is not sticky, so the spider can race back and forth along 4 it to spin the web’s trademark spiral.

Unlike some spiders that weave a new web every day, a Golden Orb Weaver 5 reuses her handiwork until it falls apart, sometimes not for two years1. The silky thread is five times stronger than steel by weight and absorbs the force of an impact three times better than Kevlar, a high-strength human-made 6 material used in bullet-proof vests. And thanks to its high tensile strength, or the ability to resist breaking under the pulling force called tension, a single strand can stretch up to 40 percent longer than its original 7 length and snap back as

well as new. No human-made fiber even comes 8 close .

It is no 9 wonder manufacturers are clamoring for spider silk. In the consumer pipeline: high-performance fabrics for athletes and stockings that never run2. Think parachute cords and suspension bridge cables. A steady 10 supply of spider silk would be worth billions of dollars — but how to produce it？ Harvesting silk on spider farms does not 11 work because the territorial arthropods have a tendency to devour their neighhors.

Now, scientists at the biotechnology company Nexia are spinning artificial silk modeled after Golden Orb dragline. The 12 first step: extract silk-making genes from the spiders. Next, implant the genes into goat egg cells. The nanny goats that grow from the eggs secrete dragline silk proteins in their 13 milk . “The young goats pass on the silk-making gene without 14 any help from us,” says Nexia president Jeffry Turner. Nexia is still perfecting the

spinning process, but they hope artificial spider silk will soon be snagging customers 15 as fast as the real thing snags bugs.

第十篇 Chicken Soup for the Soul：

Mashed potatoes, macaroni and cheese, may be bad for your arteries．1but according to a study in Psychological Science, they’re good for your heart and 2emotions ．The study focuses on “comfort food” and how it makes people feel．

"For me 3personally ,food has always played a big role in my family,” says Jordan Troisi, a graduate student at the University of Buffalo, and lead author on the study．The study came out of the research program of his co—author Shira Gabriel．It has 4looked at non-human things that may affect human emotions．Some people reduce loneliness by bonding with their 5 favorite TV show, building virtual relationships with a pop song singer or looking at pictures of loved ones．Troisi and Gabriel wondered if comfort food could have the same effect 6by making people

think of their nearest and dearest. In one experiment, in order to make 7 participants feel lonely, the researchers had them write for six minutes about a fight with someone close to them．Others were given an emotionally neutral writing assignment. Then, some people in each 8group wrote about the experience of eating a comfort food and others wrote about eating a new food． 9 Finally ,the researchers had participants 10 complete questions about their levels of loneliness．

Writing about a fight with a close person made people feel lonely．But people who were generally 11secure in their relationships would feel less lonely by writing about a comfort food．"We have found that comfort foods are consistently associated with those close to us．"says Troisi．"Thinking about or consuming these foods later then serves as a reminder of those close others．"In 12 their essays on comfort food, many people wrote about the 13 experience of eating food with family and friends. In another experiment, 14eating chicken soup in the lab made people think more about relationships, but only if they considered chicken soup to be a comfort food．This was a question they had been