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. dead bodies
C. animal waste. D. living environmet
2.According to the study described in Paragraph 4, we can learn that ______.
A. the bones studied were not from dogs brought into North America by Europeans
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. ancient dogs entered North America between 1450 and 1675 AD
3.What can we know from the passage?
A. Native Americans domesticated local wolves into dogs.
B. Ancient dogs entered North America across the Bering Land Bridge.
C. Latin America’s dogs are different from North America’s in genes.
D. Scientists discovered some ancient dog remains in 1920s.
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.The passage mainly talks 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
高一英语听力第三部分中等难度题
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. dead bodies
C. animal waste. D. living environmet
2.According to the study described in Paragraph 4, we can learn that ______.
A. the bones studied were not from dogs brought into North America by Europeans
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. ancient dogs entered North America between 1450 and 1675 AD
3.What can we know from the passage?
A. Native Americans domesticated local wolves into dogs.
B. Ancient dogs entered North America across the Bering Land Bridge.
C. Latin America’s dogs are different from North America’s in genes.
D. Scientists discovered some ancient dog remains in 1920s.
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.The passage mainly talks 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
高一英语听力第三部分中等难度题查看答案及解析
During the day, we’ll walk across the land, ____ the footprints of big animals.
A.will follow | B.follow | C.following | D.to follow |
高一英语单项填空简单题查看答案及解析
The flooding________the bridge, so we can’t walk across it forever.
A.damaged B.destroyed C.harmed D.hurt.
高一英语单项填空中等难度题查看答案及解析
He walked _________ the bridge, pushed his way ________ the crowd of people and soon came to a hut.
A. across; across B. over; through
C. over; into D. across; through
高一英语单项填空中等难度题查看答案及解析
The truth, Sir, is that the old man____ across the street when my car hit him.
A. was to walk B. had been walking
C. walked D. was walking
高一英语单项填空困难题查看答案及解析
Last Sunday morning, when I was having a walk in the park near my home, I came across a crew make a new film with one of my favorite actor. I didn’t have my camera with me at that time, but I rushed back home to get. Unfortunately, by the time I got back, they have finished the scene and the actor couldn’t be seen everywhere. I was really disappointing and about to leave when he walked out a building. He was right there in the front of me! I couldn’t believe my luck---not only did I had my photo taken with him, but he signed his name on my shirt!
高一英语短文改错中等难度题查看答案及解析
When walking down the street, I came across David, who I _____ for years.
A.didn’t see B.haven’t seen
C.hadn’t seen D.wouldn’t see
高一英语单项填空中等难度题查看答案及解析
When I walked into the house after school, the first thing I noticed was a box with items I recognized from my dad’s office.
“What are you doing home already?” I asked casually.
“Andrew, I was laid off today.” he answered quietly.
I was sure he was joking. “No, you weren’t. Why are you really home?”
Then I noticed his seriousness and realized he was telling the truth. My father has always been a hard worker and prided himself on his career. Providing for our family has been his joy, and I guess I had taken his work for granted.
My father’s unemployment created many changes in our lives. For starters, he was home all the time, which meant my bed had to be made, my room cleaned up, and my homework done right after school. I would come home every day to find him at the computer searching for jobs. I began to notice how down he seemed, and how losing his job had affected his self-esteem, though he tried to be optimistic. For the first time, I saw my dad as vulnerable. He asked my brother and me to spend less. I gave up my allowance, which even though it wasn’t much, felt like the right thing to do. I also found a part-time job.
After several difficult months of searching, my dad decided to go in a totally different direction. He explained that he never wanted to be laid off again, so he was going to start his own business. Day by day, I watched him build it, and I admired how much time and energy he expended.
One evening I asked if he needed help.
“Only if it doesn't interfere with school,” he said.
I showed up at his office the next afternoon, and most afternoons after that for two months. I always knew he was a hard worker, but watching him in action really impacted me. Although this was one of the worst experiences for our family, it taught me a lot about dealing with adversity. Now I know that through creative problem-solving, I can always find Plan B, ask for help, and take risks. What I have learned from my dad’s understanding of business and his work ethic are two of the most important lessons I will ever learn, and will be my foundations for success.
1. The author’s father stayed at home because ________.
A. he had to help with the author’s lesson
B. he had been unemployed by his company
C. heavy housework was waiting for him to do
D. he wanted the author know the truth?
2. What made the author know the truth?
A. The box from his dad’s office B. His father’s words
C. His father’s expression D. Being informed by his family
3. The author’s attitude toward his father’s former job was ________.
A. unconcerned B. sympathy C. doubt D. tolerance
4. By saying “Only if it doesn't interfere with school”, the author’s father seemed ________.
A. to refuse the author’s advice on the new business
B. to show his discontent with the author’s schoolwork
C. to have said yes to the author’s offer of help
D. to be looking forward to the author’s good behavior at school
5. It can be inferred from the text that ________.
A. the author’s father was more optimistic to stay at home
B. the author couldn’t put up with his dad’s own business
C. the author’ s father offered little allowance to the author
D. the author benefited from his father on how to deal with adversity
高一英语阅读理解简单题查看答案及解析
Most people know the feeling when you walk into a lift(电梯)with other people. A study has found that where people stand is based on their social position on entering the lift.
Rebekah Rousi, a Ph.D. student, did a study of lift behavior in two of the tallest office buildings in Adelaide, Australia. As part of her research, she took a total of 30 lift rides in the two buildings, and discovered there was a fixed order about where people chose to stand.
In her research paper, she wrote that more senior men seemed to walk straight towards the back of the lift. She said “in front of them were younger men, and in front of them were women of all ages.” She also noticed there was a difference in the direction where people look during the ride. “Men watched the monitors, looked in the side mirrors (in one building) to see themselves, and in the door mirrors (in the other building) to watch others. Women would watch the monitors and avoid looking into others’ eyes (unless in conversations) and the mirrors.”
Rebekah Rousi concluded that shyer people stand toward the front, where they can’t see other passengers, while fearless people stand in the back, where they have a good view of everyone else.
1.According to the study, where people stand in a lift is decided by ________.
A. their social position B. the monitors
C. other passengers D. others’ position
2.Who are most likely to go to the back of the lift?
A. Shyer people. B. Senior men.
C. Younger men. D. Women.
3.Which is true according to the passage?
A. The order in which people stand in a lift is fixed.
B. Few people feel embarrassed with strangers in a lift.
C. Women like watching themselves in the side mirrors.
D. Fearless people stand in the back to avoid seeing others.
4.The passage is probably taken from ________.
A. a lift instruction B. a story book
C. a travel guide D. a newspaper
高一英语阅读理解简单题查看答案及解析
Most people know the feeling when you walk into a lift(电梯) with other people. A study has found that where people stand is based on their social position on entering the lift.
Rebekah Rousi, a Ph.D. student, did a study of lift behavior in two of the tallest office buildings in Adelaide, Australia. As part of her research, she took a total of 30 lift rides in the two buildings, and discovered there was a fixed order about where people chose to stand.
In her research paper, she wrote that more senior men seemed to walk straight towards the back of the lift. She said , “in front of them were younger men, and in front of them were women of all ages.” She also noticed there was a difference in the direction where people look during the ride. “Men watched the monitors, looked in the side mirrors (in one building) to see themselves, and in the door mirrors (in the other building) to watch others. Women would watch the monitors and avoid looking into others’ eyes (unless in conversations) and the mirrors.”
Rebekah Rousi concluded that shyer people stand toward the front, where they can’t see other passengers, while fearless people stand in the back, where they have a good view of everyone else.
1.According to the study, where people stand in a lift is decided by __________.
A. their social position
B. the monitors
C. other passengers
D. others’ position
2.Who are most likely to go to the back of the lift?
A. Shyer people. B. Senior men.
C. Younger men. D. Women.
3.Which is true according to the passage?
A. The order in which people stand in a lift is fixed.
B. Few people feel embarrassed with strangers in a lift.
C. Women like watching themselves in the side mirrors.
D. Fearless people stand in the back to avoid seeing others.
4.The passage is probably taken from __________.
A. a lift instruction B. a story book
C. a travel guide D. a newspaper
高一英语阅读理解中等难度题查看答案及解析