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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(驯化) 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(后代) of which now live with people in Alaska, Canada, and the Lower 48.
Dog remains 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(永冻层) 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 North America.
Along with the Fairbanks samples, the researchers collected DNA from bones of 37 dog specimens(标本) from Mexico, Peru, and Bolivia that existed before the arrival of Columbus. In the case of both the Alaska dogs and the dogs from Latin America, the researchers found that they shared the most genetic material with gray wolves of Europe and Asia. This supports the idea of domestic dogs entering the New World with the first human explorers who wandered east over the land bridge.
Leonard and Wayne’s study suggests that dogs joined the first humans that made the adventure across the Bering Land Bridge to slowly populate the Americas. Wayne thinks the dogs that made the trip must have provided some excellent service to their human companions or they would not have been brought along. “Dogs must have been useful because they were expensive to keep,” Wayne said. “They didn’t feed on mice; they fed on meat, which was a very guarded resource.”
1. The underlined word “remains” is closed in meaning to ______.
A. leftover food B. animal waste
C. dead bodies D. living environment
2. According to the study described in Paragraph 4, we can learn that ______.
A. ancient dogs entered North America between 1450 and 1675 AD
B. the 11 bones of ancient dogs are not from native American dogs
C. the bones discovered by the gold miners were from North American wolves
D. the bones studied were not from dogs brought into North America by Europeans
3. What can we know from the passage?
A. Native Americans domesticated local wolves into dogs.
B. Scientists discovered some ancient dog remains in 1920s.
C. Latin America’s dogs are different from North America’s in genes.
D. Ancient dogs entered North America across the Bering Land Bridge.
4. 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
5.What does the passage mainly talk about ______.
A. the origin of the North American dogs
B. the DNA study of ancient dogs in America
C. the reasons why early people entered America
D. the difference between Asian and American dogs
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Coyotes(丛林狼) used to live only in wide-open spaces of western prairies and deserts. They avoided forests, where wolves, their enemies, lived. But as forests were cleared to make room for farms and communities, coyotes started spreading east and west into they newly open territories.
Most coyotes are afraid of people, so those living in cities have learned how to avoid being seen. Street-smart coyotes hunt for food between dusk and dawn, when few people are around. During the day, the animals rest in out-of-the-way spots. ”They ‘are trying to avoid people as best as they can ,” says a scientist studying coyotes around Chicago, Illinois
City life suits coyotes in several ways. There are no enemies such as mountain lions ,wolves ,or hunters. City coyotes eat well, too. Parks yards and green spaces in cities provide habitat for a feast of favorite coyote foods ,including mice ,rats and rabbits . Coyotes also eat lots of fruits , With plenty of natural food and no-predators (捕食性动物), coyotes in urban areas are healthier, live longer and raise larger families than their country cousins.
Unfortunately, some city coyotes lose their fear of humans. They find tasty garbage of pet food outside homes. They notice that people ignore them instead of chasing them away. Some humans even feed coyotes on purpose, thinking it’s an act of kindness. Actually, it’s a serious mistake.
Coyotes that become comfortable around people and learn to associate buildings and yards with food are the ones that get into trouble. Some coyotes attack pets in yards. Sometimes a coyote may even chase or bite in a human. An animal that behaves in these ways must be removed by wildlife officials.
It’s people that change coyotes’ behavior. But we’re also the ones who can help them be good neighbors. We can teach them by not providing food for them, and by making sure they know there are certain area they’re not allowed. Can coyotes and people live more safely together in cities?
68. The first paragraph is to show______________
A. where coyotes used to live
B. what coyotes’ enemies are
C. why coyotes began to live in cities
D that forests are making room for humans
69. Why does city life suit coyotes?
A. People are nice to them
B. There are more green spaces
C. There is enough good and no enemies
D They can hunt for food at dusk
70. Some city coyotes are not afraid of humans maybe because______________
A. they are being protected by wildlife officials
B. people chase them away when seeing them
C. some people provide them with food sometimes
D they are allowed to stay indoors.
71. What is the purpose of this passage?
A. To introduce a kind of wolf-coyotes to readers.
B. To persuade people to move away from where Coyotes live
C. To enjoy the harmony between coyotes and humans,
D To call on people to live more safely with coyotes.
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听力
第一节
听下面5段对话。每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
M：Would you like a red skirt?
W：No．I don’t like red skirt．
M：How about yellow, green?
W：Yes．But they are too short．
M：We have some longer ones but they are orange．
W：Good．I like orange best．
1．hat color does the girl like best？
A．Yellow．
B．Green．
C．Orange．
W：I really enjoyed meeting your parents．I hope they like me．
M：Don’t worry．I’m sure they’ll say yes．
2．hat’s the probable relationship between the two speakers?
A．Husband and wife．
B．A girl and her boyfriend．
C．Teacher and student．
M：Do you have to go now?
W：Yes, I’m afraid I do．I’ll get up at 6∶30 tomorrow to catch the first bus, and to be at work at 7∶30 in my factory．
3．hat are the two speakers doing?
A．Catching the earliest bus．
B．Working in a clothes factory．
C．Saying goodbye to each other．
M：I’d like a first-class ticket to London．
W：Fine．The next flight leaves at 4 p. m．
4．here are the two speakers?
A．In a classroom．
B．At a booking office．
C．At a railway station．
M：When do you serve lunch?
W：Around 12 o’clock．But you can order some drinks now．
M：Are they free of charge?
W：For soft drinks, yes．
5．hat can you know from the conversation?
A．It is 12 o’clock now．
B．Drinks are free of charge．
C．Soft drinks are free of charge．
第二节
听下面5段对话或独白。每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项。听每段对话或独白前,你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听第6段材料,回答第6～8题。
W：Tom, I have some presents for you and Tim．You can choose two of them．
M：Why not three?You have five here．
W：Because you choose first．
M：Then ask Tim to choose first．
6．How many presents does the woman have?
A．2．
B．3．
C．5．
7．Why doesn’t Tom want to choose first?
A．He thinks Tim should choose first．
B．He doesn’t like the presents．
C．He wants to get more presents．
8．Who will choose first?
A．Tom．
B．Tim．
C．It’s hard to say．
听第7段材料，回答第9～11题。
W：I’ve had this terrible pain in my back for three days now．I couldn’t get to sleep till around five o’clock this morning．Can you give me something for it?
M：Without a prescription, the strongest thing I can give you is aspirin．In the old days we used to be able to give out all kinds of medicine without a prescription, but these days the laws have changed and I can’t give you anything strong enough to help without a prescription．
W：Gee．Aspirin isn’t strong enough and I don’t have an appointment with my doctor until the end of the week．
M：What’s your doctor’s name?
W：My doctor is Dr Anderson．
M：Oh, Dr Anderson, I know him．He’s certainly a wonderful fellow．I’ll tell you what I can do．I can call Dr Anderson and ask him for a prescription right over the phone．I’m sure he can do that．
W：That would be wonderful．I really need to get some strong pain killers as soon as I can．Do you think he’ll still be in his office?
M：Sure, I know he stays late at the clinic every day to perform experiments．
W：Great．
M：You just relax and we’ll get you fixed up in no time．
9．Why is the man going to call Dr Anderson?
A．To tell him the woman is coming．
B．To make an appointment．
C．To fill the prescription．
10．Which is NOT true?
A．The woman needs drugs to kill her pain．
B．The woman thinks aspirin will solve her problem．
C．The man and the woman both like Dr Anderson．
11．Why does Dr Anderson stay late at the office?
A．He lives there．
B．He does experiments after work．
C．He loves his work．
听第8段材料,回答第12～14题。
W：Hello, China Airlines．What can I do for you, sir
M：Hello, I’d like to ask if you have the tickets to Beijing on Friday afternoon．
W：Wait a minute, please．Yes, we have．One is at 1∶30,the other at 3∶45．
M：May I have two at 3∶45?
W：Sorry, we have only one left．Would you please have the ones at 1∶30?
M：All right．
W：Thank you．When will you come for the tickets?
M：How about this afternoon?
W：OK．Bye．
12．What are they talking about?
A．Airlines．
B．Booking airline tickets．
C．The timetable of China Airlines．
13．On which day will the man leave for Beijing?
A．Friday．
B．Sunday．
C．Monday．
14．Which flight does he get at last?
A．The 1∶30 flight．
B．The 3∶45 flight．
C．The 5∶00 flight．
听第9段材料,回答第15～17题。
M：I’d like to book a ticket to Beijing．
W：What day are you planning to go?
M：I’m supposed to be in Beijing on the morning of the fourteenth, but I’d rather get there on the evening of the thirteenth．
W：What time would you like to leave?
M：Late in the afternoon, after work．
W：We’ve a flight at four thirty．
M：That’s too early．I don’t get out of work until five．Do you have a later flight？
W：The next flight is at five thirty, but there are only back seats left．What about another at six thirty？We still have some seats on the flight on the thirteenth, and it only takes you an hour and a half to get into Beijing．
M：Oh, good, I’d better take the six thirty．By the way, do they serve dinner on the flight？
W：Yes, they do．
15．Which flight does the man decide to take?
A．The six thirty flight．
B．The five thirty flight．
C．The four thirty flight．
16．What time will the man get into Beijing?
A．At five on the afternoon of the fifteenth．
B．At nine on the morning of the fourteenth．
C．At eight on the evening of the thirteenth．
17．Where will the man have supper most probably on the day when he leave for Beijing?
No one can call back yesterday．昨日不会重现。
A．At home．
B．On the plane．
C．In a restaurant．
听第10段材料,回答第18～20题。
Goats always seem to be the second best to other farm animals．They give milk, but not as much as cows do．They provide wool, but not as much as sheep do．They carry loads, but not as well as horses do．However, goats have their own special strong points．They develop well on weeds and small branches that would make cattle and sheep sick．They can live just about anywhere since they need very little space．Years ago, city residents even raised goats in their backyard．Goats can also climb just about anything, and they can even live on the steep slopes of mountains．In fact, the animal seems healthiest and happiest when there is something for them to climb．Because of all these above, goats are raised for their milk, meat, hair and leather in many parts of the world．
18．Why does the speaker say that goats are the second best to other animals?
A．They’re much smaller．
B．They don’t produce much．
C．They learn more slowly．
19．Why are goats popular in some areas?
A．They can live on steep slopes．
B．The are particularly healthy animals．
C．Their leather is very valuable．
20．What can goats provide?
A．Wool and fur．
B．Milk and meat．
C．All above．