Read the advertisements, and then choose the best answers.

Driver Wanted

1). Clean driving license   2). Must be of smart appearance.    3). Aged over 25.

Apply to：Capes Taxis, 17 Palace Road, Boston

Air Hostesses for International Flight Wanted

1). Applicants must be between 20 and 33 years old.

2). Height 1.6m to 1.75m.    3). Education to GCSE standard.

4). Two languages. Must be able to swim.

Apply to: Recruitment office, Southern Airlines, Heathrow Airport West HR37KK

Teachers Needed

For private language school. Teaching experience unnecessary.

Apply to: The Director of Studies, Instant Language Ltd, 279 Canal Street

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    Salt plays an important role in our daily diet. Even a small reduction(减少) in salt in the diet can be a big help to the heart. A new study used a computer model to predict -how just three grams less a day would affect heart disease in the United States.

    The result: Thirteen percent fewer heart attacks. Eight percent fewer strokes（中风）. Four percent fewer deaths. Eleven percent fewer new cases of heart disease. And two hundred forty billion dollars in health care savings. Researchers found it could prevent one hundred thousand heart attacks and ninety-two thousand deaths every year．

    The study is in the New England Journal of Medicine. Kirsten Bibbins-Domingo at the University of California San Francisco was the lead author. She says people would not even notice a difference in taste with three grams, or one-half teaspoon, less salt per day. The team also included researchers at Stanford and Columbia University.

    Each gram of salt contains four hundred milligrams of sodiu(钠), which is how foods may list their salt content．

    The government says the average American man eats ten grams of salt a day. The American Heart Association advises no more than three grams for healthy people. It says salt in the American diet has increased fifty percent since the nineteen seventies, while blood pressures have also risen. Less salt can mean a lower blood pressure.

    New York City Mayor Michael Bloomberg is leading an effort called the National Salt Reduction Initiative. The idea is to put pressure on food companies and restaurants. Critics call it government interference(干预).

    Mayor Bloomberg has already succeeded in other areas, like requiring fast food places in the city to list calorie information. Now a study by the Seattle Children's Research Institute shows that the calorie information on the menu can influence what parents order for their children. Ninety-nine parents of three to six year olds took part. Half had calories between the two groups for foods that the parents would have chosen for themselves. McDonald's menus clearly showing how many calories were in each food. Parents given the counts chose an average of one hundred two fewer calories when asked what they would order for their children. Yet there was no difference in calories between the two groups for foods that the parents would have chosen for themselves.

    Study leader Pooja Tandon says even small calorie reductions on a regular basis can prevent weight gain over time. The study was published in the journal Pediatrics.

    Four people in England back in 1953, stared at Photo 51,It wasn't much—a picture showing a black X. But three of these people won the Nobel Prize for figuring out what the photo really showed –the shape of DNA The discovery brought fame and fortune to scientists James Watson, Francis Crick, and Maurice Wilkins. The fourth, the one who actually made the picture, was left out.

    Her name was Rosalind Franklin.” She should have been up there,” says historian（历史学家） Mary Bowden.” If her photos hadn't been there, the others couldn't have come up with the structure.” One reason Franklin was missing was that she had died of cancer four years before the Nobel decision. But now scholars（学者）doubt that Franklin was not only robbed of her life by disease but robbed of credit by her competitors

    At Cambridge University in the 1950s, Watson and Click tried to make models by cutting up shapes of DNA's parts and then putting them together. In the meantime, at King's College in London, Franklin and Wilkins shone X-rays at the molecule(分子). The rays produced patterns reflection the shape.

    But Wilkins and Franklin's relationship was a lot rockier than the celebrated teamwork of Watson and Crick, Wilkins thought Franklin was hired to be his assistant .But the college actually employed her to take over the DNA project.

    What she did was produce X-ray pictures that told Watson and Crick that one of their early models was inside out. And she was not shy about saying so. That angered Watson, who attacked her in return, “Mere inspection suggested that she would not easily bend. Clearly she had to to go or be put in her place.”

    As Franklin's competitors, Wilkins, Watson  and Crick had much to gain by cutting her out of the little group of researchers, says historian Pnina Abir-Am. In 1962 at the Nobel Prize awarding ceremony, Wilkins thanked 13 colleagues by name before he mentioned Franklin, Watson wrote his book laughing at her. Crick wrote in 1974 that  “Franklin was only two steps away  from the solution.”

    No, Franklin was the solution. “She contributed more than any other player to solving the structure of DNA . She must be considered a co-discoverer,” Abir-Am says. This was backed up by Aaron Klug, who worked with Franklin and later won a Nobel Prize himself. Once described as the “Dark Lady of DNA”, Franklin is finally coming into the light.

    Many people believe that language belongs to human beings. However, cats have developed a language not for each other, but for the human beings who have them as pets.

    When communicating with each other, cats “talk” with a system of signals. Their tails, rather than any kind of “speech”, act as an important way to express themselves. They also touch each other to express s their feelings. With other cats, they will use their voices only to express pain. Unbelievable, all of that changes when a human walks into the room. Cats use many different kinds of vocal (声音的) expressions when they communicate with a person. Since these vocal expressions are not used to communicate with other cats, it seems that cats developed this “language” to communicate with their human owners.

    This fact is shown more clearly when watching rooms that have only one cat and those with several cats. An only cat is usually very vocal, since the only creature(动物)around with whom the cat can communicate is its owner. Cats with other cats, though, are much quieter. If they want to have a conversation, they only need go to other cats and communicate in their natural way.

    Since cats learned to meow(喵喵叫)for the only purpose of communicating with human owners should take the time to learn what their different meows mean. If an owner knows, to name just a few examples, which meow means the cat is hungry, which means the cat wants to be petted, and which means the cat wants to have a little “conversation”, the relationship between cat and owner will be closer.

    The summer before my dad died, we moved house. Up until that point, our family had our own space to spread out. Money was tight, so there was no television set, but we owned a turntable on which my dad's records played constantly. Mostly, it played Bob Dylan. Tracks from The Basement Tapes and Desire became an important part of our new life. My brother and I, aged 8 and 10，climbed trees, built hideaways and learned the words of Clothes Line Saga. We would chant over and over, lost in our own joy.

    It was January when my dad left us forever because of the cancer. He was 36 going on 37 then, the same age as Dylan. Afterwards, our laughter disappeared, but we kept on playing the records, which became our only ritual of remembrance. The two men became so intertwined in my head, I struggled to tell them apart.

    Dylan was my dad's gift to me. What child wouldn't be fascinated by songs full of pirates and seasick sailors? How did it feel to have No direction home? Farewell, Angelina became my party-piece. I would sing this at church cheese and wines to the assembled audience. A lot of donations were made.

    Growing up, I remained a fan of the music, but I wasn't obsessed with Dylan until one day in early 1995, my brother bought us both tickets to see him play at Brixton Academy. London felt like a long way to go. But finally seeing Dylan step out on to the stage brought a sudden rush of excitement.

    I have seen Dylan a couple of times since. My brother is not around so much these days. But he was up for a visit recently. We passed a happy evening laughing and drinking, while his son, aged nine, performed his party—piece Subterranean Homesick Blues for us. He sang it word-perfect. And so it goes on: Dylan's music as a gift, passed down the generations.

    If you have a chance to take a walk in a park, look carefully at the people walking their dogs. You'll probably find friendly-looking people with friendly dogs; quiet people with quiet dogs; large men with oversized dogs and long-haired women with long-eared dogs. As you've probably noticed, dogs and their owners look alike. Have you ever wondered why?

    These similarities are so common that researchers have tried to explain them. There are two theories (理论): the convergence (趋同) theory and the selection theory. The convergence theory says that as the owner and the dog spend more time together, they influence each other to the point where they grow similar. In other words, they “converge.” The selection theory, on the other hand, says that owners are interested in dogs that look like them, so they choose those dogs as pets.

    Recently, researchers at the University of California decided to test the two theories by taking pictures of 45 dogs separately from their owners. Then they asked some students to match the dogs' photos with their owners. The students were quite successful with purebred (纯种的) dogs: they correctly matched 16 out of 25 with their owners. However, they had almost no success connecting mixed-breed (杂交的) dogs with their owners. When owners select a purebred dog, they can easily predict (预测) what it will look like later. But that is not true with mixed-breed dogs because it's hard to predict what a mixed-breed dog will look like when it grows up. And since it was the purebreds not the mixed-breeds that looked like their owners, the research seems to prove the “selection theory”.

    But one bit of warning. Although many people look like their dogs, not all dog owners enjoy having the similarity pointed out to them. So, even if the similarity is amazing, don't go up to a stranger and say, “Wow, you look just like your dog!”