Researchers at Sweden’s KTH Royal Institute of Technology say they have found further proof that the wolf ancestors of today’s dogs can be from southern East Asia -- findings that are contrary to theories placing the birth place in the Middle East. Dr Peter Savolainen, KTH researcher in evolutionary genetics, says a new study released Nov. 23 confirms that an Asian region south of the Yangtze River was the principal and probably the only region where wolves were domesticated(驯化)by humans.
Research data show clearly that dogs are descended from wolves, but there’s never been scientific agreement on where in the world the domestication process began. “Our analysis of Y-chromosomal(染色体)DNA now confirms that wolves were first domesticated in Asia south of Yangtze River -- we call it the ASY region -- in southern China or Southeast Asia,” Savolainen says.
The Y data supports previous evidence from mitochondrial(线粒体)DNA. “Taken together, the two studies provide very strong evidence that dogs appeared first in the ASY region,” Savolainen says.
Archaeological data and a genetic study recently published in Nature suggest that dogs originate from the Middle East. But Savolainen rejects that view. “Because none of these studies included samples from the ASY region, evidence from ASY has been overlooked,” he says.
Peter Savolainen and PhD student Mattias Oskarsson worked with Chinese colleagues to analyse DNA from male dogs around the world. Their study was published in the scientific journal Heredity.
Approximately half of the gene pool was universally shared everywhere in the world, while only the ASY region had the entire range of genetic diversity. “This shows that gene pools in all other regions of the world most probably originate from the ASY region,” Savolainen says.
“Our results confirm that Asia south of the Yangtze River was the most important -- and probably the only -- region for wolf domestication, and that a large number of wolves were domesticated,” says Savolainen.
In separate research published recently in Ecology and Evolution, Savolainen, PhD student Arman Ardalan and Iranian and Turkish scientists conducted a comprehensive study of mitochondrial DNA, with a particular focus on the Middle East. Because mitochondrial DNA is inherited only from the mother in most species, it is especially useful in studying evolutionary relationships.
“Since other studies have indicated that wolves were domesticated in the Middle East, we wanted to be sure nothing had been missed. We find no signs whatsoever that dogs originated there,” says Savolainen.
In their studies, the researchers also found minor genetic contributions from crossbreeding between dogs and wolves in other geographic regions, including the Middle East.
“This subsequent dog/wolf hybridisation(混合淡化技术)contributed only modestly to the dog gene pool,” Savolainen explains.
1.What does Dr. Peter Savolainen believe?
A. Dogs’ ancestors came from the Middle East.
B. Wolves were probably first trained to work for humans in the ASY region.
C. Analysis of Y-chromosomal DNA should be combined with mitochondrial DNA.
D. Samples of the previous studies are enough to support the conclusion.
2.We can learn from the passage that _______.
A.there is a universal agreement on the place of first domestication
B.data from ASY may highlight where dogs came from
C.Dr. Savolainen’s research mainly focuses on the Middle East
D.the dog/wolf hybridization makes up most of the dog gene pool
3.What is special about mitochondrial DNA?
A.It is only used in studying evolutionary relationships.
B.It alone can provide hard evidence for Savolainen’s research.
C.It is the most useful in finding out the birth place of dogs.
D.It comes from the mother of most animals and plants.
高三英语阅读理解中等难度题
Researchers at Sweden’s KTH Royal Institute of Technology say they have found further proof that the wolf ancestors of today’s dogs can be from southern East Asia -- findings that are contrary to theories placing the birth place in the Middle East. Dr Peter Savolainen, KTH researcher in evolutionary genetics, says a new study released Nov. 23 confirms that an Asian region south of the Yangtze River was the principal and probably the only region where wolves were domesticated(驯化)by humans.
Research data show clearly that dogs are descended from wolves, but there’s never been scientific agreement on where in the world the domestication process began. “Our analysis of Y-chromosomal(染色体)DNA now confirms that wolves were first domesticated in Asia south of Yangtze River -- we call it the ASY region -- in southern China or Southeast Asia,” Savolainen says.
The Y data supports previous evidence from mitochondrial(线粒体)DNA. “Taken together, the two studies provide very strong evidence that dogs appeared first in the ASY region,” Savolainen says.
Archaeological data and a genetic study recently published in Nature suggest that dogs originate from the Middle East. But Savolainen rejects that view. “Because none of these studies included samples from the ASY region, evidence from ASY has been overlooked,” he says.
Peter Savolainen and PhD student Mattias Oskarsson worked with Chinese colleagues to analyse DNA from male dogs around the world. Their study was published in the scientific journal Heredity.
Approximately half of the gene pool was universally shared everywhere in the world, while only the ASY region had the entire range of genetic diversity. “This shows that gene pools in all other regions of the world most probably originate from the ASY region,” Savolainen says.
“Our results confirm that Asia south of the Yangtze River was the most important -- and probably the only -- region for wolf domestication, and that a large number of wolves were domesticated,” says Savolainen.
In separate research published recently in Ecology and Evolution, Savolainen, PhD student Arman Ardalan and Iranian and Turkish scientists conducted a comprehensive study of mitochondrial DNA, with a particular focus on the Middle East. Because mitochondrial DNA is inherited only from the mother in most species, it is especially useful in studying evolutionary relationships.
“Since other studies have indicated that wolves were domesticated in the Middle East, we wanted to be sure nothing had been missed. We find no signs whatsoever that dogs originated there,” says Savolainen.
In their studies, the researchers also found minor genetic contributions from crossbreeding between dogs and wolves in other geographic regions, including the Middle East.
“This subsequent dog/wolf hybridisation(混合淡化技术)contributed only modestly to the dog gene pool,” Savolainen explains.
1.What does Dr. Peter Savolainen believe?
A. Dogs’ ancestors came from the Middle East.
B. Wolves were probably first trained to work for humans in the ASY region.
C. Analysis of Y-chromosomal DNA should be combined with mitochondrial DNA.
D. Samples of the previous studies are enough to support the conclusion.
2.We can learn from the passage that _______.
A.there is a universal agreement on the place of first domestication
B.data from ASY may highlight where dogs came from
C.Dr. Savolainen’s research mainly focuses on the Middle East
D.the dog/wolf hybridization makes up most of the dog gene pool
3.What is special about mitochondrial DNA?
A.It is only used in studying evolutionary relationships.
B.It alone can provide hard evidence for Savolainen’s research.
C.It is the most useful in finding out the birth place of dogs.
D.It comes from the mother of most animals and plants.
高三英语阅读理解中等难度题查看答案及解析
Mars Was Not Always Bitterly Cold
Scientists at the California Institute of Technology (Caltech) have reported evidence that Mars was warmer and wetter long ago than it is today. The Caltech scientists say they have directly established the temperature of Mars four billion years ago. At least, they established the surface temperature on part of the planet at that time. The researchers say it is the first such evidence to be discovered and presented.
The Caltech scientists say carbonate(碳酸盐) minerals formed on Mars at about eighteen degrees Celsius. They reached the finding after studying a meteorite(陨石) that had its beginnings near the Martian surface.
Today, the average temperature on Mars is sixty-three degrees below zero Celsius.
The finding was reported on the website of the National Academy of Sciences. Caltech Assistant Professor Woody Fischer helped to prepare the report. He says eighteen degrees Celsius is not especially cold or hot. He says this makes the finding extremely interesting. Knowing the temperature can give scientists an idea of the climate on Mars long ago. It can also help them decide whether the planet had liquid water. Spacecraft orbiting Mars have shown what appear to be rivers, lakebeds and mineral deposits. These pictures suggest that, at one time, water did flow there. Mars Rover vehicles and other spacecraft have confirmed the information.
Caltech Geology Professor John Eiler was another writer of the report. He says knowing the temperature of Mars from long ago provides valuable information. It shows that early in the planet's history, at least part of Mars could support a climate like that of Earth.
The meteorite the scientists examined is one of the oldest known rocks in the world. It is called the Allan Hills meteorite. Its name came from the place in Antarctica where it was found in 1984. The meteorite is believed to have blown loose from the Mars' surface when another space rock struck its "home."
1. The underlined word “establish” in Paragraph 1 probably means “___________”.
A.to set up |
B.to make people accept a belief |
C.to discover or prove |
D.to start having a relationship with others |
2.How did the scientists reach the finding?
A.By studying Allan Hills meteorite. |
B.By using spacecraft orbiting Mars. |
C.By studying minerals gathered on Mars |
D.By studying a meteorite on the Martian surface. |
3.According to the fourth paragraph, what have spacecraft orbiting Mars done?
A.Measuring the temperature of Mars. |
B.Taking photos of the surface of Mars. |
C.Confirming that there is water flowing on Mars. |
D.Finding where human beings will probably land on Mars. |
4.How did Allan Hills meteorite get its name?
A.From its original place on Mars. |
B.From where it was found on the earth. |
C.From the name of the scientist who found it. |
D.From the name of the aircraft that discovered it |
5. Where can we most probably read this passage?
A.In a biography of scientists. |
B.In a geography magazine. |
C.In an environment report. |
D.In a science report. |
高三英语阅读理解中等难度题查看答案及解析
阅读下面短文,在空白处填入1个适当的单词或括号内单词的正确形式。
Researchers at the Canadian Institute for Advanced Research show how the interaction (交互) between remembering and forgetting in the brain 1. (allow) us to make more intelligent decisions 2. (base) on memory. They published a new review paper in the journal Neuron.
Forgetting makes us smart by working with memorizing 3. the following ways, the researchers say. First, letting go of outdated information lets us adapt to new situations. By forgetting the old and potentially misleading information, we can adapt to new environments 4. (easy). Second, forgetting also makes decision- making simple. We just remember the important information which makes it easy for us 5. (make) wise decisions.
What and how much we remember can 6. (decide) by our environments, For example, a lawyer or a designer with a set of clients will likely remember 7. (they) names for a longer period of time, A cashier who has a changing sea of 8. (customer) every day will only remember names for a short amount of time.
The researchers point out that the motto is true: If you don’t use it, you lose it. But as 9. review paper shows, it can be a good thing. Clearing out the information you don’t need can help make room for the important things, 10. can make you become more intelligent.
高三英语语法填空中等难度题查看答案及解析
ATTENTION,ALL OUR NEW STUDENTS:
Welcome to West Lakes Institute of Technology.You are strongly advised to adhere to the following three basic rules on your first day of the second semester:
1.Wear your pre-admission student number on your lapel(衣服的翻领)at all times.
2.Do not enter any classroom where classes are already in progress.
3. When asked to provide,basic information about yourself,be ready to show your green enrollment acceptance advice slip.
Students who have pre-paid the enrollment fee
9:00 a.m.to 10:00 a.m.(no later)you should visit the foyer of the Old Chapel building to receive your new student information kit.Once you have your kit,you are not required until 10:30 a.m.,so you can relax in the Student Centre until you are called over the PA system.
Students who are yet to pay the enrollment
Go directly to the Admissions Centre and be prepared to pay your enrollment fee($150 cash only)to the New Admissions Officer.You will be asked for your address and your preadmission student number(the number on your green enrollment acceptance advice slip).Note that this is NOT the number which is later displayed on your student card.Once you have paid your enrollment fee, follow the instructions above for students who have pre-paid their fee.
Student Cards
Student cards will not be issued until Thursday.Photographs,however,will be taken on Monday afternoon.Make your way to the Library at the following times:
1:00 p.m.-Film and Photographic Arts
1:45 p.m.-Marketing
2:30 p.m.-Travel&-Tourism
3:15 p.m.-Hotel Hospitality
4:00 p.m.--Fashion&Design
4:45 p.m.-all other Art students
Photographs of students in all other courses will be taken Tuesday afternoon.
Welcome Address
The Director of the college will address all new students in the Main Hall at around 10:45 a.m.When you hear the announcement that directs you to assemble in the Main Hall,make your way swiftly past the canteen area,through the courtyard and into the Hall.No food or drinks are allowed in the Main Hall.
Lunch
The canteen is situated on the ground floor of the student building.Since the canteen is also used by members of the public,you will be asked to produce your enrollment acceptance advice slip.Failure to do this will result in all purchases being charged for at non-discount prices.Cooked lunches,are,served only between 12:15 p.m.and.1:30 p.m.
Student Information Kits
The latest student information kit contains a 52-page booklet which tells you where you should go in the afternoon.Look on page three to find the course you have enrolled in,and follow the instructions given.Areas designed for the various tutorial sessions for each course are listed on page 4 to 6.If you are required to have your photograph taken during a group tutorial session,quietly excuse
yourself,and return to the session as soon as possible.
1.According to the passage,students who have already paid the fee
A.should give their address and student number to the New Admissions Officer
B.can enter any classroom to have a rest
C.are required to receive their kit before 9 o'clock
D.can have a minimum of 30 minutes to relax after getting the kit
2.We can learn from the text that"students' enrollment acceptance advice slip_____”
A.displays the same number as that on the student card.
B.allows students to buy things in the canteen at a lower price
C.is only essential to students who haven't paid the fee in advance
D.is required when taking the pictures used for the student cards
3.Which of the following statements is TRUE according to the text?
A.Marketing students can get their 'student cards at 1:45,Monday afternoon.
B.Students are allowed to have their lunch at 12:30 p.m.in the Hall.
C.The assembly call will be made before the welcome address begins.
D.Students can get their student cards from the Library.
4.We can learn from the last paragraph that during a group tutorial session,
A.you can take a picture
B.you can do anything you like
C.you can leave for the photograph requirement
D.you can read a 52-page book
高三英语阅读理解中等难度题查看答案及解析
41. During her study in Massachusetts Institute of Technology she has got the degree _____ PhD, and it is a degree ______ chemistry.
A.of; at | B.in; at | C.of; in | D.in; of |
高三英语单项填空简单题查看答案及解析
Scientists at Royal Holloway, University of London and Queen Mary, University of London have discovered that bees learn to fly the shortest possible route between flowers even if they discover the flowers in a different order. Bees are effectively solving the “traveling salesman problem”, and they are the first creatures found to do this.
The traveling salesman must find the shortest route that allows him to visit all locations on his route. Computers solve it by comparing the length of all possible routes and choosing the shortest, and it can keep computers busy for days. However, bees solve it without computer assistance using a brain the size of grass seed. Dr. Nigel Raine, from the School of Biological Sciences at Royal Holloway explains, “Bees solve traveling salesman problems every day. They visit flowers at multiple locations and because bees use lots of energy to fly, they find a route which keeps flying to a minimum. ”
The team used the computer to control artificial flowers to test whether bees would follow a route defined by the order in which they discovered the flowers or if they would find the shortest route. After exploring the location of the flowers, bees quickly learned to fly the shortest route.
As well as improving our understanding of how bees move around the landscape pollinating(授粉)crops and wild flowers, this research, which is due to be published in The American Naturalist, has other applications. Our lifestyle relies on networks such as traffic on the roads, information flow on the Web and business supply chains. By understanding how bees can solve their problems with such a tiny brain, we can improve our management of these everyday networks without needing lots of computer time. Dr. Raine adds, “Despite their tiny brains, bees are capable of extraordinary feats of behavior. We need to understand how they can solve the traveling salesman problem without a computer. ”
1. What would be the best title of the passage?
A. Bees help salesmen travel
B. Tiny-brained bees solve a complex mathematical problem
C. How bees discover the flowers
D. How to solve the “traveling salesman problem”
2.We may infer from the second paragraph that the “traveling salesman problem” .
A. can be solved by a computer easily
B. can’t even be solved by a computer
C. can puzzle both people and computers
D. remains to be solved by scientists
3. The main purpose of the last paragraph is to .
A. provide further proof for the research
B. tell us how bees can fly the shortest route between flowers
C. tell us how the research about bees’ flying route was conducted
D. explain the importance of the research
4. It can be concluded from the passage that .
A. all creatures are smarter than computers
B. the research about bees’ flying route can be applied to many fields
C. our networks are more complex than bees’ ones
D. with the help of the computer we can find out how bees can solve the “traveling salesman problem”
高三英语阅读理解中等难度题查看答案及解析
“Suzanne Meyer, the assistant director of the English Language Institute at the University of Tennessee, says that many students need to learn how to collect information, and then evaluate the information and apply it to a new context. Meyer says: “1. . Question-asking activities help students to become better language learners. Question-asking may help develop critical thinking skills by allowing for more interactions.2. . When they are confident, they can have more interaction. That extra interaction might lead to critical thinking.”
How can you practice asking questions? There are many strategies to improve question-asking and develop critical thinking skills. 3. .
If students were reading a new text, they would design a series of questions using three different steps. In the first step, students create questions about information in the text that they are reading. In the second step, students create questions about how the information in the text connects to their own life. In the third step, students create questions about abstract ideas – ideas that came up in the questions about themselves.4. .
Practical Tips: Meyer says that when teachers tell students which questions to answer, students are less likely to be creative about the types of questions that they ask. 5. . Try making a list of questions that go from concrete to abstract. Check with your teacher to make sure that your grammar is correct, and try to practice in the classroom.
A.So, practice developing your own questions!
B.People who can ask questions should be very confident.
C.People can ask questions freely when they feel relaxed.
D.If people take some steps, they can find some useful question-asking patterns.
E.There are many benefits to using question-asking activities with English learners.
F.One possible strategy is to use question-asking patterns that start with concrete questions and move to abstract questions.
G.If students follow these three steps, they have not only practiced creative ways to ask questions, they have also started practicing critical thinking.
高三英语七选五中等难度题查看答案及解析
At the well-known research institute at Princeton, they have a number of laboratories with computers _________ each room.
A.equipping with B.equipped C.equipped with D.equipping
高三英语单项填空中等难度题查看答案及解析
Confucius Institute
The Confucius Institute at the University of Minnesota offers several short classes on Chinese language and culture.
★Class Fees
The cost of classes is $225 ($170 for Chinese Rehab)
★Class Calendar
The Confucius Institute follows the University of Minnesota semester schedule. The Confucius Institute classes start a few weeks after the start of the University semester and last for ten class sessions. Classes are not held on University holidays.
The upcoming class sessions will be:
Spring 2018: February 1- April 7
Summer 2018: June 13- August 25
Tentative class calendar:
The schedule may change due to teacher availability.
MONDAY | TUESDAY | WEDNESDAY | THURSDAY |
Beginning I, Section A 6:00 ~ 7:30 p.m. | Beginning I, Section B 6:00 ~ 7:30 p.m. | Beginning II 6:00 ~ 7:30 p.m. | Intermediate II 6:00 ~ 7:00 p.m. |
Chinese Rehab 6:30 ~ 7:00 p.m. | Intermediate I 6:00 ~ 7:30 p.m. | Beginning III 6:00 ~ 7:30 p.m. | Intermediate III 6:00 ~ 7:30 p.m. |
★Class Cancellations
Any class not meeting minimum enrollment by four business days before the class start date will be cancelled and you will be contacted. If we must cancel a class due to insufficient enrollment or any other circumstance beyond our control, we will offer a full refund or issue credit towards another class.
★Contact Information
The Confucius Institute is located within the University International Center on the east bank of the Twin Cities campus. The University International Center is located in the Keeler Apartment building. Enter at the corner of 17th Avenue S.E. and 4th Street through the doors located near the “University International Center” sign.
Office hours
The office is generally open Monday through Friday, from 8:00 a.m. until 4: 30 p.m.
The office is closed daily from12:.00 noon until 1: 00 p. m. and is closed on all University holidays.
Office Address
160 University International Center, 331-17th Ave. S.E., Minneapolis, MN 55414
Phone: 612625-5080
Fax: 612-625-5158
Email: confucius@ umn. edu
1.Chinese Rehab ________________.
A. costs more money
B. is held on Monday
C. lasts one and a half hours
D. has four classes a week
2.To get information about the classes, you can visit the office ___________.
A. on Monday noon
B. at 12:30 a.m., Tuesday
C. on Wednesday evening
D. at 1: 30 p.m., Friday
3.What is True about the classes?
A. The schedule may be changeable.
B. They can be one-to-one instruction.
C. They are held on University holidays.
D. They start at the beginning of the University semester.
高三英语阅读理解简单题查看答案及解析
Frederick M. Hess is the director of education policy studies at the American Enterprise Institute, which is a nonprofit organization that conducts research on many public issues. He says that a long summer vacation doesn’t make sense in today’s world.
Can American students afford to take a summer vacation? In a summer vacation, millions of kids spend valuable time sending messages, watching TV, playing video games and doing shopping in the mall. They will also be putting their academic futures at risk.
Summer vacation once made sense in the past when you didn’t need an education to get a good job. But now things have changed. For today’s students, academic skills are important to students’ future success, but such skills are affected in the summertime. Many nations don’t give kids an American-style summer vacation. They offer no more than seven consecutive(连续的) weeks of vacation. Most American school districts offer up to thirteen weeks. To compete in the global marketplace, Americans must be prepared to go up against international competitors.
Summer vacation also causes challenges for today’s families. In the 1960s, more than 60% of families had a stay-at-home Mom. Now two-thirds of American children live in households where every adult works. For these families, summer vacation can be more burden than break. Someone must watch the kids.
But the biggest problem may be how summer vacation hurts academic achievement. Researchers have found that disadvantaged students lose significant ground in the summertime.
A longer school year does not have to be an invitation to hard boring work. Rather, it should allow time-pressed teachers to conduct richer and more imaginative lessons. Schools would have more time to devote to athletics, languages, music and the arts. Summer vacation can be a grand thing. But in the 21st century, it may also be outdated.
Title: Summer Vacation
Theme | A long summer vacation isn’t 1. in today’s world. | |
Basic Information | 2. length | 13 weeks in most American schools |
Students’ 3. | ·Sending messages and watching TV ·Playing video games ·Doing shopping | |
Disadvantages | ·4. student’s academic skills and putting academic futures at risk. ·Being a 5. to families for they have to watch kids. ·Hurting students’ academic achievement and resulting in 76 significant ground. | |
Suggestion | A longer school year does not have to 6. to hard boring work. Richer and more imaginative lessons should be 7. , such as athletics, languages, music and the arts. | |
8. | Though being a ground thing, summer vacation might be out of 9. in the 21st century. | |
高三英语其他题中等难度题查看答案及解析