Have you ever heard a news reporter talk about DNA? Reporters talk about DNA found at the scene of a crime. They talk about police finding DNA “fingerprints.” Police sometimes use DNA as a clue to find out who committed the crime.
DNA is a substance（物质） that makes up genes. Everything alive has genes. Plans have genes. Animals have genes. Yo
u have genes.
Genes are the basic units of heredity（遗传）. Heredity means all the characteristics you inherit from your parents. You get your genes from your parents. You inherit half of your genes from your mother. You inherit half of your genes from your father.
Genes are a kind of code. A tree’s genes tell w
hat shape its leaves will be. A cat’s genes tell what color its fur will be. Your genes tell what color your eyes will be. Your genes tell what color your hair will be. Everything about you co
mes from the code in your genes.
Genes line up on strands（链） called chromosomes（染色体） in cells. Everything alive is made up of cells. Chromosomes are in the center, or nucleus, of cells.
Different parts of you are made of different kinds of cells. Your muscles are made of muscle celIs. Your skin is made of skin cells. The code in your genes tells your body to make different kinds of cells. The genes in each cell tell the cell how to work. They tell the cell when to make new copies of itself.
An Austrian monk named Gregor Mendel first saw inherited patterns in pea plants. He experimented with pea plants in the 1860s. One of the things, or traits（特质）， Mendel studied was what makes some pea plants tall and some short. He said that the traits must come from units of heredity passed from the parent plants. These units were later called genes.
In the mid-1900s, scientists discovered that genes are made of DNA. In the 1970s, scientists learned how to change DNA with genetic engineering. Scientists also learned that problems with certain genes cause diseases. Muscular dystrophy, cystic fibrosis, and hemophilia are some genetic diseases-diseases caused by problems in genes. Today, scientists are looking for ways to cure genetic diseases by changing genes through a process called gene therapy. What is DNA?
| A．DNA is a kind of gene. |
| B．DNA is a substance that makes up genes. |
| C．DNA is the basic unit of heredity. |
| D．DNA is a measure to protect crime. |
Which of the following about genes is correct according to the passage?
| A．Plants, animals and human beings have the same genes. |
| B．Half people inherit all genes from their mother, others from their father. |
| C．Genes decide the trees shapes, the cats’ fur color and our eyes’ color as well. |
| D．Genes will give you a code when you need them. |
Where are genes?
| A．Genes lining up on strands called chromosomes are in the center of cells. |
| B．Genes hide in everything alive in your body. |
| C．Genes can be nowhere but in your mind, controlling all your actions. |
| D．Genes travel in your body and help cope skin, muscle, and eyes. |
An Austrian monk named Gregor Mendel .
| A．first saw inherited patterns in people |
| B．was interested in why plants were different |
| C．first called the units of heredity from parents genes |
| D．was the first who discovered genes |
We can conclude that .
| A．scientists were less intelligent than monks in 1900s |
| B．some genes are bad and can cause diseases |
| C．we don’t need to worry about genetic diseases any longer |
| D．the discovery of genes may be of great help in our daily life |
A dog’s tail can tell you a lot more than you might think. Is it wagging (摇) to the left or is it wagging to the right?
“The direction of tail wagging does in fact matter，”said Giorgio Vallortigara，a professor at the University of Trento in Italy. Professor Vallortigara finds that the way the tail is wagging can tell you a lot about a dog’s state of mind—whether you’re a human or another dog.
What’s the difference between a left wag and a right wag？Professor Vallortigara and his colleagues have studied 43 dogs of various breeds — German Shepherds，Beagles，Boxers，Border Collies and some mutts. They find that if a dog wags its tail to the left. it’s feeling anxious or nervous. The reason could be an unfamiliar or dangerous situation，an unfamiliar person，or an unfamiliar and possibly threatening dog. But if the tail is wagging to the right，it means the dog is feeling relaxed and approachable.
“The tail is a very important signal，”said Thomas Reimchen，a biologist at the University of Victoria in British Columbia, Canada. ”There is a lot of visual information that dogs use when communicating with each other. ”
How did the scientists figure all this information out? They had the dogs in their study watch videotapes of other dogs. When the dog on the tape wagged its tail to the right，they say the other dogs remained calm and cool. But when the dog on the tape wagged its tail to the left，the other dogs got anxious.
The researchers are still not exactly sure if the direction of tail wagging is something the dog does consciously. They suspect that it might be something the dog does without even thinking about it — kind of like when you get goose bumps if something scares or startles you. They plan to do more research to get more information about what dogs are thinking and feeling while they’re wagging. As Reimchen said，“I'm not going to be surprised if we find all sorts of really interesting processes that nobody has ever seen before. ”Professor Vallortigara’s study focused on the relationship between_________.
| A．a dog’s state of mind and its owner's feeling |
| B．a dog’s state of mind and the direction of its tail wagging |
| C．a dog’s sense of direction and its state of mind |
| D．a dog’s intention of tail wagging and its feeling |
According to the study，dogs which wag their tails to the left may feel_________.
| A．calm | B．happy | C．angry | D．nervous |
It is implied in Thomas Reimchen’s words in Paragraph 4 that___________.
| A．dogs’ tails play all important role in their growth |
| B．dogs show their feelings only by wagging their tails |
| C．dogs get to know others by watching tail wagging |
| D．dogs can understand each other by repeating tail wagging |
How does the passage mainly develop?
| A．By asking and analyzing questions |
| B．By making comparisons |
| C．By following the order of time |
| D．By providing examples |
The scene in the Hollywood movie The Day After Tomorrow, when global warming could soon turn the global climate into a new ice age, may never occur, according to a new research.
The next ice age could be 15,000 years away, say European scientists who last month announced a continuous record of 740,000 years of climate data obtained from the Antarctic ice.
Scientists from 10 nations have now almost completely drilled through a 3,000-meter depth of ice high in the Antarctic mainland. They figure out that the area, where summer temperatures can fall to – 40℃, has at least 900,000 years of snowfalls, kept as neatly as the growth rings of a tree. And the ice and air caught in each layer(层) have begun to answer questions about the climates in the past..
The results show that there have been eight ice ages in the past 740, 000 years and eight warmer periods. And by comparing the pattern of global conditions today with those of the past, the researchers reported in Nature that the present warm period could last another 15, 000 years.
Research suggests that there is a very close connection between greenhouse gas levels and global average temperatures. It also shows that carbon dioxide (二氧化碳) levels are the highest for at least 440,000 years.
"If people say to you: ‘the greenhouse effect is a good thing because we would go into an ice age otherwise,’ our data say no, a new ice age is not hanging over our heads,” said Eric Wolff from the British Antarctic Survey. "Now we have eight examples of how the climate goes in and out of ice ages… and you can learn what the rules are that go into the climate models that tell us about the future."
Scientists found that whenever temperatures rose in the frozen record, so did carbon dioxide level. "In 440,000 years we have never seen greenhouse gas get as thick as it is today," said Dr Wolff.In drilling through the ice in Antarctica, scientists have found that______.
| A．the lowest temperature there is – 40℃ |
| B．the depth of ice is 3,000 meters |
| C．the ice has existed for 15,000 years |
| D．snowfalls are kept in certain patterns |
The information of the global climate conditions in the past can be obtained through______.
| A．separating carbon dioxide from the air |
| B．examining the growth rings of trees |
| C．comparing temperatures in different areas |
| D．studying the ice and air caught in each layer |
We can infer from Eric Wolff's words that_______.
| A．there is something wrong with the data |
| B．greenhouse effect is always a bad thing |
| C．a new ice age will not come in the near future |
| D．greenhouse gas will get thick in the future |
What would be the best title for the passage?
| A．Research over the Antarctic area. |
| B．Warm period to last about 15, 000 years. |
| C．Report on the eight ice ages in the past. |
| D．Hollywood movies and the global climate. |
Money is the root of all evil and new study claims there may be some truth behind the saying．Scientists at the University of California, Berkeley, US，announced on February 27 that rich people are more likely to do unethical (不道德的) things, such as lie or cheat, than poorer people．
The scientists did a series of eight experiments. They published their findings online in the Proceedings of the National Academy of Sciences (PNAS,《美国国家科学院院刊》)．
They carried out the first two experiments from the sidewalk near Berkeley. They noted that drivers of newer and more expensive cars were more likely to cut in on other cars and pedestrians at crosswalks. Nearly 45 percent of people driving expensive cars ignored a pedestrian compared with only 30 percent of people driving more modest cars．
In another experiment, a group of college students was asked if they would do unethical things in various everyday situations. Examples included taking printer paper from work and not telling a salesperson when he or she gave back more change. Students from higher-class families were more likely to act dishonestly.
According to the scientists, rich people often think money can get them out of trouble. This makes them less afraid to take risks. It also means they care less about other people’s feelings.
Finally，it simply makes them greedier．“Higher wealth status seems to make you want even more，and that increased want leads you to bend the rules or break the rules to serve your self-interest,” said Paul Piff, leading scientist of the study.
Piff pointed out that the findings don’t mean that all rich people are untrustworthy or that all poor people are honest. He said the experiments were to show how people living in different social situations express their instincts and values in different ways.By saying “money is the root of all evil”，the author wants to ____________．
| A．draw readers’ attention to the research |
| B．1ink wealth with bad behavior |
| C．show how the saying proves the findings |
| D．defend rich people who do unethical things |
What makes rich people unethical according to the scientists?
a．they become more selfish b．they have more desires
c．they believe money talks d．they welcome risks
| A．a、b | B．a、b、d |
| C．b、c | D．a、b、c |
Why did the scientists do the experiments?
| A．To show how social status affects people's ethics． |
| B．To show people’s instincts and values in different ways. |
| C．To test whether the saying “money is the root of all evil” is true． |
| D．To show the difference between higher-class people and lower-class people． |
What does the article really want to show us?
| A．Money is the root of all evil． |
| B．The rich are more likely to act badly． |
| C．The saying is unreasonable． |
| D．All rich people are untrustworthy． |
Thousands of people began pouring into Pennsylvania from other states. They wanted to buy lottery tickets. The tickets cost only $ 0.9 each. But that small spending could bring them a reward of $ 90 million .That was the second largest lottery jackpot （积累奖金）in history.
More than 87 million tickets were bought for the Pennsylvania lottery drawing. Those who bought tickets had to choose seven numbers from 1 to 80．The chance of winning was one in 9.6 million, but that little chance certainly didn’t affect ticket sales. In the last few days before the drawing, tickets were sold at the unbelievable rate of 500 per second.
Experts say many people buy lottery tickets because they just want to have a piece of the action. Others say the lottery is a stock market for poor people. It allows them to dream about wealth they’ll probably never have.
But many people believe lotteries are no better than legalized gambling. Some critics note that most people who play are poor and may not be able to afford the tickets. There are also many addicts who take the game seriously. They may pour their life savings into lottery tickets. Some clubs have been formed to help them kick the habit.
Politicians like lotteries because they provide money that would otherwise have to come from new taxes. The profits from lotteries are usually used to pay for education or programs for senior citizens. But critics say this arrangement just allows states to legalize vice(恶习), under the name of social progress. Whether you regard stock lotteries right or not, you cannot refuse to accept their extreme popularity with many Americans.The main idea of the passage is that __________.
| A．lotteries are of great benefit to everyone who buys them |
| B．playing a lottery is just like investing in the stock market |
| C．many people buy lottery tickets , but lotteries cause disagreement |
| D．lotteries are nothing but legalized vice |
Which of the following is TRUE according to the passage?
| A．Politicians like lotteries because they don’t have to pay extra taxes. |
| B．The popularity of lotteries in America actually is social progress. |
| C．Some critics don’t like lotteries because many poor people waste money on them. |
| D．People love the lottery because it is a stock market. |
In just one hour in the last few days, the Pennsylvania lottery sold tickets totaling_______.
| A．$ 1.62 million | B．$ 1.82 million |
| C．$ 9.6 million | D．$ 87 million |
People who are addicted to playing lotteries should __________.
| A．join a support group | B．kick the habit |
| C．win the lottery | D．save every cent |
The arts, especially music, should be part of every school's lessons at every grade level. Students would be much smarter if they had some musical experience. They could improve their classroom skills, like paying attention and following directions. People develop all these skills when they learn music. Making music also lets children use their imagination. It provides students with a chance to try out their own ideas.
Music not only makes children better students, but also gives them something positive to do. In a music program, children can be part of a band instead of joining a gang(团伙). Parents can enjoy listening to their children's music instead of seeing them glued to a computer or TV screen. In a school band, students get to be part of a team. They can get along well with old friends and make new friends through music.
Music builds self-confidence, too. It gives children a sense of achievement and success. Making music is something for them to be proud of, and it lets kids practice performing in front of an audience. Music gives children an opportunity for self-expression, and that helps develop their self-confidence.
Once again, music is important because it can make children better students, give them something positive to do, and build their character. That is why music should be offered in every single grade in every school.According to the passage, music could make students smarter by __________.
| A．improving their classroom skills and paying attention |
| B．improving their classroom skills and imagination |
| C．improving their attention, direction and imagination |
| D．learning music, making music and trying out their own ideas |
What does the underlined phrase "glued to" in the second paragraph mean?
| A．unwilling to turn on | B．always looking |
| C．unwilling to leave | D．always playing |
The third paragraph mainly tells us that music could _______________.
| A．give children self-expression and self-confidence |
| B．bring to children achievement and success |
| C．give children something to be proud of |
| D．develop children's self-confidence |
What's the best title of this passage？
| A．Music is a must as a course at school |
| B．Music builds children's self-confidence |
| C．Music makes students much smarter |
| D．Learning music and making music |
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