When people first walked across the Bering Land Bridge thousands of years ago, dogs were by their sides, according to a study published in the journal Science. Robert Wayne of the University of California, Los Angeles, and Jennifer Leonard of the Smithsonian Institute, used DNA material--some of it unearthed by miners in Alaska--to conclude that today's domestic dog originated in Asia and accompanied the first humans to the New World about 10,000 to 15,000 years ago. Wayne suggests that man's best friend may have enabled the tough journey from Asia into North America. "Dogs may have been the reason people made it across the land bridge," said Wayne. "They can pull things, carry things, defend you from fierce animals, and they're useful to eat." Researchers have agreed that today's dog is the result of the domestication  of wolves thousands of years ago. Before this recent study, a common thought about the precise origin of North America's domestic dog was that Natives domesticated local wolves, the descendents  of which now live with people in Alaska, Canada, and the Lower 48. Dog _ from a Fairbanks-area gold mine helped the scientists reach their conclusion. Leonard, an evolutionary biologist, collected DNA from 11 bones of ancient dogs that were locked in permafrost  until Fairbanks miners uncovered them in the 1920s. The miners donated the preserved bones to the American Museum of Natural History in New York City, where they remained untouched for more than 70 years. After borrowing the bones from the museum, Leonard and her colleagues used radiocarbon techniques to find the age of the Alaska dogs. They found the dogs all lived between the years of 1450 and 1675 A.D., before Vitus Bering and Aleksey Chirikov who were the first known Europeans to view Alaska in 1741. The bones of dogs that wandered the Fairbanks area centuries ago should therefore be the remains of "pure native American dogs," Leonard said. The DNA of the Fairbanks dogs would also expose whether they were the descendents of wolves from... The first humans into the New World brought dogs along with them because   _  . A) dogs fed on mice B) dogs were easy to keep C) dogs helped protect their resources D) dogs could provide excellent service
D


For nearly a century before there was such a thing as a space program,a view of space was possible.People could see full views of the Moon,explore Mars ,and study the outer space beauty.All of this was made possible by a small group of artist-astronomers  who worked to show people how other worlds in space might look. Lucien Rudaux,a French artist,was the first to use his artistic ability and his knowledge of astronomy in art.His paintings show a mixture of skilled observations,brilliant imagination and careful attention.As a result,many of his works have come surprisingly close to actual conditions on distant planets.His painting of Mars included moonlike craters  that were first photographed by the astronauts in 1965.His 1930 painting of a dust storm looks remarkably like a photograph of a storm taken by the astronauts in 1976. The artist-astronomers,including Rudaux,made people interested in outer space by painting what turned out to be exact portraits of the planets. According to the passage,artist-astronomers spent their lives   _  . A) exploring the planets B) studying paintings C) painting the planets D) producing spaceships
C


Q: Jesse Owens is recognized as a hero not just because he is fast. Some people might say that they know him for just that reason. However, there are lots of fast people who are not known. Jesse Owens is known because Chancellor Adolf Hitler did not shake the hand of Jesse Owens or even recognize his feat of winning four gold medals, because Owens was an African American. Jesse Owens owed much of his success to his coach Charles Riley, who probably was the most important one making him have the career that he did. Owens came from a background that required him to work after school in a shoe shop. He couldn't attend the regularly scheduled track practices organized by his school. However, Charles Riley saw the boy had both a passion  and a talent for running, and so arranged for him to be able to practice before school instead. Jesse Owens achieved this success despite  his racial background, which at the time was a huge limitation to him. He could only eat in certain restaurants and sleep in certain hotels, as could all African Americans of the time. He was also never offered a scholarship for school despite setting records for NCAA  championships. The Berlin Olympics in 1936 is where his star rose as high as it would ever be able to. These Olympics were during the height of Hitler's rule. It took courage to race in front of Hitler and many other racist . It took time, determination, and perseverance  to race like him. He won four gold medals at those Olympics. It would take almost fifty years for someone else to walk away from the Olympics with four gold medals. He passed away at the age of 66 from lung cancer. According to the passage, which of the following about Jesse Owens is true? A) Hitler recognized his feat of winning four gold medals. B) He was offered a scholarship for setting records for NCAA championships. C) He could only eat in certain restaurants like many other African Americans. D) It took him almost fifty years to walk away from the Olympics with four gold medals.
A: C


*Question*
Owning pet birds is not just feeding them when necessary. You have to be very responsible if you have decided to keep birds as pets. If you really want to acquire a companion, think in advance whether you are able to handle it. Depending on what pet bird you are going to have and how big it is, the cost is different. For example, the cost of a comfortable cage, the cost for nutritional food and the money for some additional things should be taken into consideration. There are also some unexpected cost. For example, when your pet bird gets sick, you have to send for a vet  . You may think that you do not have free time to have a dog so you'd better have a pet bird because it doesn't require a lot of attention. You are wrong! Some people even do not have time for a short sleep. They will not have enough time for pets, either. For good bird health it is very important to handle them and play with them as much as you can. Also there are a lot of people who think that birds do not require a lot of space and they are wrong again. They also need to fly so if you do not have space for it, you'd better reconsider the things.  But do not forget the great advantage of having a pet bird. In the animal kingdom, birds rank near the top when it comes to smarts. You can have a friend for life if you take good care of it. It's a real character and can bring joy and colour in your home. What is the text mainly about? A) The advantages of keeping a pet bird. B) The reasons for keeping a pet bird. C) Things to consider if you want to keep a pet bird. D) Different types of pets for different people.
**Answer**

C