A recent study of ancient and modern elephants has come up with the unexpected conclusion that the African elephant is divided into two distinct (不同的) species
The discovery was made by researchers at York and Harvard universities when they were examining the genetic relationship between the ancient woolly mammoth and mastodon to modern elephants—the Asian elephant, African forest elephant and African savanna elephant
Once they obtained DNA sequences (序列) from two fossils (化石)，mammoths and mastodons， the team compared them with DNA from modern elephants. They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths.
The scientists used detailed genetic analysis to prove that the African savanna elephants and the African forest elephants have been distinct species for several million years. The divergence of the two species took place around the time of the divergence of Asian elephants and woolly mammoths. This result amazed all the scientists.
There has long been debate in the scientific community that the two might be separate species but this is the most convincing scientific evidence so far that they are indeed different species.
Previously, many naturalists believed that African savanna elephants and African forest elephants were two populations of the same species despite the elephants’ significant size differences. The savanna elephant has an average shoulder height of 3.5metres while the forest elephant has an average shoulder height of 2.5metres. The savanna elephant weighs between six and seven tons, roughly double the weight of the forest elephant. But the fact that they look so different does not necessarily mean they are different species. However, the proof lay in the analysis of the DNA.
Alfred Roca, assistant professor in the department of Animal Sciences at the University of Minois, said, “We now have to treat the forest and savanna elephants as two different units for conservation purpose. Since 1950 all African elephants have been conserved as one species. Now that we know the forest and savanna elephants are two very distinct animals, the forest elephant should become a bigger priority (优先)for conservation purpose .”
1.One of the fossils studied by the researchers is that of ________.
A. the Asian elephant B. the forest elephant
C. the savanna elephant D. the mastodon elephant
2.The underlined word “divergence” in paragraph 4means “________”
A. evolution B. exhibition C. separation D. examination
3.The researcher’s conclusion was based on a study of the African elephant’s _____
A. DNA B. height C. weight D. population
4.What were Alfred Roca’s words mainly about?
A. The conservation of African elephants.
B. The purpose of studying African elephants
C. The way to divide African elephants into two units
D. The reason for the distinction of African elephants
5.Which of the following can be the best title for the passage?
A. Naturalist’s Belief about Elephants.
B. Amazing Experiment about Elephants
C. An Unexpected Finding about Elephants
D. A Long scientific Debate about Elephants
Baths have long been considered of medical importance to man. In Greece there are the ruins of a water system for baths built over 3,000 years ago. The Romans had warm public baths. In some baths, as many 3,000 persons could bathe at the same time.
Treating disease by taking bathing has been popular for centuries. Modern medical bathing first became popular in Europe and by the late 1700’s has also become popular in the United States.
For many years frequent bathing was believed to be bad for one’s health. Ordinary bathing just to keep clean was avoided, and perfume was often used to cover up body smells!
By the 1700’s doctors began to say that soap and water were good for health. They believed that it was good for people to be clean. Slowly, people began to bathe more frequently. During the Victorian Age of the late 19th century, taking a bath on Saturday night became comon.
In the United States ordinary bathing was slow to become popular. During the 18th and early 19th centuries, many Americans were known as “The Great Unwashed!” In one American city , for example, a person was only allowed to take a bath every thirty days! That was a law!
Frequency of bathing today is partly a matter of habit. People know that bathing for cleanliness is important to health, Doctors know that dirty bodies increase the chance of diseases. As a result, in the United States, people generally bathe often. Some people bathe once a day at least. They consider a daily bath essential to good health.
1.A water system for baths was built by _______ over 3,000 years ago.
A. the Romans B. the Greeks
C. the Americans D. the Europeans
2.Dirty bodies can ______ .
A. ruin one’s business B. cause disease
C. drive customers away D. cause good health
3.In the 18th century doctors believed that being clean was .
A. unimportant B. good for health C. harmful D. important
4.The underlined word perfume probably means .
A. a sweet smelling substance B. good health
C. a strange smelling substance D. large wealth
5.Which of the following gives the main idea of the passage?
A. Everybody in America takes a daily bath.
B. We should often take baths
C. Taking baths has become popular in the world.
D. Bathing has become easier and cheaper.
A 33-year-old financial analyst in California recently quit his job to devote himself to an unpaid job teaching math on the Internet, and his lessons are reaching almost 100,000 people a month. Salman Khan’s voice is heard every day on the net --- by tens of thousands of students around the world who are hungry for help learning math. He has posted 1,200 lessons on YouTube ... lessons that appear on an electronic blackboard, which range from basic addition to advanced mathematics for science and finance. And they are free.
Khan lives in Silicon Valley, with his wife, a doctor, and their new baby. He got the idea for his “Khan Academy” four years ago, when he taught a young cousin how to convert kilograms to grams. With Khan’s help, the cousin got good at math, and Khan began a new career.
Now, Khan records his lessons himself, but he never goes on camera. “It feels like my voice in their head. You’re looking at it and it feels like someone’s over your shoulder talking in your ear, as opposed to someone at the blackboard, which is distant from you,” he said.
When Springfield High School in Palo Alto, California invited Khan to speak in person --- he immediately connected to the students there.
The idea of short lessons that can be played over and over again attracted high school senior Bridget Meaney. She says she had trouble with math in the seventh grade. “I think the teachers are good, but they can’t teach at a speed that’s perfect for everyone,” she said. “I like the idea of learning something in class but then going back and pressing pause or rewind and actually getting a deeper understanding of it.”
Originally, Khan kept his lessons short because of YouTube restrictions. Now, he thinks short is better. “Education researchers now tell me that 10 minutes is how long someone can have a high level of concentration. And anything beyond that and your brain switches off,” he said.
For Khan, teaching math, science, and finance is just the beginning. He says he’s ready to expand his YouTube site to include other subjects as well.
1.What gave Khan the idea of teaching math online?
A. His success in helping his cousin learn math.
B. His discovery that many students found learning math difficult.
C. A suggestion made to him at a local high school.
D. His interest in Internet teaching.
2.Why does Khan never go on camera?
A. He’s too shy to show his face on camera.
B. It’s restricted by YouTube for education videos.
C. He wants to keep distance from the viewers.
D. He wants to create a more relaxed learning atmosphere.
3.From the passage, we know that ________.
A. Khan travels to many schools to promote his lessons
B. Khan plans to include more subjects in the future
C. Khan gives live math lessons every day for free
D. Khan set up the Khan Academy with his wife
4.Why does Bridget Meaney like Khan’s lessons?
A. Khan teaches seventh grade math better than her teacher.
B. The lessons can be watched repeatedly until fully understood.
C. She can perfectly follow the pace of Khan’s teaching.
D. She cannot concentrate when learning in class.
5.What does Khan mean by “short is better” in the 6th paragraph?
A. Keeping the lessons short can ensure better concentration.
B. YouTube recommends short lessons for its site.
C. Short lessons encourage students to return to the website.
D. Students enjoy short mathematics lessons more.
Food sometimes gets poisoned with harmful things. A person who eats such food can get an illness called food poisoning. Food poisoning is usually not serious, but some types are deadly. The symptoms of food poisoning usually begin within hours of eating the poisoned food. Fever is one of the most common symptoms.
Certain microorganisms（微生物）cause most types of food poisoning. Bacteria and other microorganisms can poison eggs, meat, vegetables, and many other foods. After entering the body, these tiny living things release（释放）poisons that make people sick.
Some chemicals can also cause food poisoning. They are often added to food while it is being grown, processed, or prepared. For example, many farmers spray chemicals on crops to kill weeds and insects. Some people may have a bad reaction to those chemicals when they eat the crops.
Some plants and animals contain natural poisons that are harmful to people. These include certain kinds of seafood, grains, nuts, seeds, beans, and mushrooms.
When people handle food properly, the risk of food poisoning is very small. Microorganisms multiply rapidly in dirty places and in warm temperatures. This means that people should never touch food with dirty hands or put food on unwashed surfaces. Food should be kept in a refrigerator to stop microorganisms from growing. Meat needs to be cooked thoroughly to kill any dangerous microorganisms. People should also wash food covered with chemicals before eating it. Finally, people should not eat wild mushrooms or other foods that grow in the wild. Some of these foods may contain natural materials that are poisonous to humans. In addition, some types of fish can be poisonous.
Most people recover from food poisoning after a few days of resting and drinking extra water. If people eat natural poisons, they must go to the hospital right away to have their stomachs emptied.
1.Which of the following statements is NOT true?
A. Food when poisoned can make people sick.
B. Food poisoning means death.
C. Food poisoning comes in varieties.
D. Food poisoning can be serious.
2.We know from the passage that the symptoms of food poisoning .
A.are always accompanied by a fever
B.are too common to be noted
C.can be noticed within hours
D.can he ignored
3.Food poisoning can be caused by all the following EXCEPT .
A.some chemicals
B.low temperatures
C.some tiny living things
D.certain natural materials
4.From Paragraph 5,we can learn that .
A.mushrooms should not be eaten
B.vegetables are safer than meat and seafood
C.natural poisons are more dangerous than chemicals
D.different types of food should be handled differently
5.It can be inferred from the passage that .
A.natural materials are safe in food processing
B.chemicals are needed in food processing
C.food poisoning can be kept under control
D.food poisoning is out of control
Just now, I entered the website “Topic for Today”. I feel 1 (interest) in the report on middle school students’ using cell-phones on campus. In fact, more students now come to school 2 cell-phones. My schoolmates have different opinions. Some think 3 is convenient to get in touch with others with the cell-phone, which also makes you feel safe especially in time of trouble. 4 , it is nice to enjoy_____5__(variety)functions of different cell-phones. 6 think differently. First, the cell-phone is not 7 must in school, as there are some IC phones there, 8 _(make) it easy to call others. Second, many students often play e-games and send e-massages with their cell-phones, even in class, 9 ___will surely have bad effects on their study. What’s more, it ___10_____(result) in a great waste of time and money. In my opinion, the cell-phone is a useful tool in our daily life. But it doesn’t mean we can use freely in school.
One day an out of worik mime(哑剧演员) was visiting the zoo and attempted to earn some money as a street performer. As soon as he started to draw a 31)______, a zoo keeper grabbed him and dragged him into his office. The zoo keeper explained to the mime that the zoo’s most popular attraction, a gorilla, had died suddenly and the keeper feared that 32)_____ at the zoo would fall off. He offered the mime a job to 33)______ the gorilla until they could get another one. The mime 34)______.
So the next morning the mime put on the gorilla suit and entered the cage before the crowd came. He discovered that it was a35)_______ job. He could sleep if he wanted, play and 36)______ people and he drew bigger crowds than he ever had as a mime. 37)_____, eventually the crowds got tired of him and he got tired of just swinging on tails. He 38)_______ to notice that he people were paying more attention to the lion in the cage next to his. Not wanting to lose the attention of his audience, he climbed to the top of his cage, crawled across a partition(隔墙), and dangled(悬荡) from the top to the lion’s cage. Of course, this made the lion very angry, but the crowd 39)______ it.
At the end of the day, the zoo keeper came and gave the mime a 40)______ for being such an attraction. Well, this went on for some time, the mime kept 41)______ the lion, the crowds grew larger, and his salary kept going up. Then one terrible day when he was dangling over the angry lion, he slipped and fell. The mime was 42)______.
The lion gathered itself and prepared to pounce(猛扑). The mime was so scared that he began to run round and round the cage with the lion close 43)______. Finally, the mime started screaming and yelling, “Help me,help me!”, but the lion was quick and pounced. The mime soon found himself flat on his back, looking up at the angry lion and the lion said, “44)______you fool! Do you want to get us 45)_______.”
1.A.ticket B.profit C.crowd D.lesson
2.A.reputation B.cost C.confidence D. attendance
3.A.take care of B.dress up as C.make up for D. keep up with
4.A.declined B.hesitated C.accepted D. doubted
5.A.great B.demanding C.meaningless D. busy
6.A.make fun of B.communicate with C.cooperate with D.take advantage of
7.A.Surprisingly B.However C.Therefore D.Additionally
8.A.failed B.refused C.managed D. began
9.A.loved B.feared C.forgot D. excused
10.A.warning B.direction C.rise D. punishment41. 11.A.fighting B.insulting C.boring D. frightening
12.A.caught B.attacked C.terrified D.offended
13.A.behind B.ahead C.beyond D.aside
14.A.Hurry up B.Get up C.Wake up D. Shut up
15.A.helped B.killed C.favored D. fired
