Ocean animals have been getting bigger over the last half-billion years. Not a little bigger. Not even a lot bigger. They have mushroomed gigantically, scientists now conclude.
Their new finding lends support for something known as “Cope’s rule.” It holds that animals tend to evolve into species that are much larger than their distant ancestors. This hypothesis(假说)takes its name from the 19th century paleontologist Edward Drinker Cope. While studying fossils(化石), he was the first to notice this trend.
Noel Heim is a paleontologist at Stanford University in Palo Alto, Calif. He also is a co-author of the new study. His team compared the body size of animals between the Cambrian Period and modern times. This was a span of 542 million years. The animals studied included species from more than 17,000 genera. They ranged from ancient trilobites, plesiosaurs (extinct reptiles with a long neck and flippers) and many less familiar creatures to today’s whales and clams.
Ocean animals today are an average of 150 times larger than they were during the Cambrian, Heim’s group reports. The smallest animals alive today — tiny crustaceans called ostracods — are only about one-tenth the size of the Cambrian’s tiniest animals. But today’s largest ocean animals — whales — are more than 100,000 times bigger than the biggest in the Cambrian.
“Classes of animals that were already big … tended to live longer,” Heim says. They also tended to change more than classes of animals that were small did.
The size gains in ocean animals are much larger than would be expected by chance, saysJonathan Payne. He’s a co-author who also works at Stanford.
The scientists don’t know what drives the trend. One possibility is an arms race(军备竞赛)between predators and prey. The idea here is that larger animals are less likely to become some other animals’ meal. Another possibility has to do with oxygen. Land animals evolved from species that started in the ocean. Some of these land animals eventually returned to the ocean. And they kept the ability to breathe oxygen-rich air. That may have made it easier for them to outgrow animals that had to filter(过滤)their oxygen out of the water.What current animals may best illustrate “mushroomed” in paragraph one?
| A．Plesiosaurs. | B．Ostracods. |
| C．Whales. | D．African Elephants. |
What is the third paragraph mainly about?
| A．The result of the study. |
| B．The participants of the study. |
| C．The significance of the study. |
| D．The targeted animals of the study. |
The ocean animals’ change in size ______.
| A．is determined by environment |
| B．cannot be predicted by any factor |
| C．is fully explained by the new study |
| D．relates to the size of their ancestors |
In the last paragraph, the explanations for the trend suggest that ______.
| A．bigger animals will never be eaten |
| B．land animal can get oxygen more easily |
| C．oxygen is important to all ocean animals |
| D．land animals can grow bigger than ocean animals |
Jane Austen, a famous English writer, was born at Steventon, Hampshire, on December 16,1775,and died on July 18,1817.She began writing early in life, although the prejudices of her times forced her to have her books published anonymously(匿名).
But Jane Austen is perhaps the best known and best loved of Bath's many famous local people and visitors. She paid two long visits here during the last five years of the eighteenth century and from 1801 to 1806,Bath was her home. Her deep knowledge of the city is fully seen in two of her novels, Northanger Abbey and Persuasion, which are largely set in Bath. The city is still very much as Jane Austen knew it, keeping in its streets and public buildings the well-ordered world that she described so well in her novels. Now the pleasure of learning Jane Austen's Bath can be enhanced (增强)by visiting the Jane Austen Centre in Gay Street. Here, in a Georgian town house in the heart of the city, you can find out more about Bath in Jane Austen's time and the importance of Bath in her life and work.
The Centre has been set up with the help and guidance of members of the Jane Austen Society. After your visit to the Centre, you can look round the attractive shop, which offers a huge collection of Jane Austen related books, cards and many specially designed gifts. Jane Austen quizzes are offered to keep the children busy.
You can also have walking tours of Jane Austen's Bath, which is a great way to find out more about Jane Austen and discover the wonderful Georgian city of Bath. The tour lasts about one and a half hours. The experienced guides will take you to the places where Jane lived, walked and shopped.Jane Austen paid two long visits to Bath _______.
| A．in her early twenties | B．in her early teens |
| C．in her late twenties | D．in her late teens |
What can we learn about Bath from the passage?
| A．Bath has greatly changed since Jane Austen's death. |
| B．The city has changed as much as Jane Austen knew it. |
| C．Bath remains almost the same as in Jane Austen's time. |
| D．No changes have taken place in Bath since Jane Austen's time. |
The author writes this passage in order to_______.
| A．attract readers to visit the city of Bath |
| B．ask readers to buy Austen's books |
| C．tell readers about Jane Austen's experience |
| D．give a brief introduction to the Jane Austen Society |
It takes you about one and a half hours_______.
| A．to get to the Jane Austen Centre in Gay Street |
| B．to buy Jane Austen related books, cards and gifts |
| C．to find a guide to take you to the Centre |
| D．to look around the city of Bath on foot |
Ever since news of widespread food recalls caused by a carcinogenic dye broke, there has been confusion(混淆) over possible links to the country of the same name, but Sudan officials say there is no connection whatever.
Sudan1 is a red industrial dye that has been found in some chilli powder, but was banned in food products across the European Union (EU) in July 2003.
Since the ban was put in place, EU officials have been striving to remove some food products from the shelves. So far 580 products have been recalled.
Last week Sudan's Embassy in the United Kingdom asked the Food Standards Agency (FSA) for clarification of the origin of the dye's name.
Omaima Mahmoud Al Sharief, a press official at Sudan's Embassy in China, explained the purpose of the inquiry was to clear up any misunderstanding over links between the country and the poisonous dye.
“We want to keep an eye on every detail and avoid any misunderstanding there,” she said. “Our embassy to Britain asked them how the dye got that name and whether the dye had something to do with our country. But they told us there was no relationship.”
The FSA, an independent food security watchdog in Britain, received a letter from the Sudanese embassy last week.
“They asked us why the dye is named Sudan, however, we also do not know how it got the name,” she said. “People found the dye in 1883 and gave it the name. Nobody knows the reason, and we cannot give any explanation before we find out.”
Sudan dyes, which include Sudan1 to 4,are red dyes used for colouring solvents(溶剂),oils, waxes, petrol, shoe and floor polishes. They are classified as carcinogens by the International Agency for Research on Cancer.What does the underlined word mean in Paragraph One?
| A．Causing cancer. | B．Having side effect. |
| C．Containing poison. | D．Poisonous. |
How did the Sudan1 get its name?
| A．The dye is often produced in Sudan. |
| B．The dye has something to do with the country named Sudan. |
| C．Nobody is sure of the origin of the name. |
| D．Many foods produced in Sudan contain the dye. |
We can infer from the passage that _______.
| A．the Sudan government is paying much attention to the food safety |
| B．Sudan1 is often used to be added to the food |
| C．people didn't realize the danger of Sudan1 until 2003 |
| D．many food shops will be closed down |
Which of the following is the best title?
| A．Keep away from Sudan1 |
| B．No Sudan1 dye links to the country |
| C．How Sudan1 dye got its name |
| D．Pay attention to the food safety |
Five years ago, David Smith wore an expensive suit to work every day.“I was a clothes addict(迷),” he jokes.“I used to carry a fresh suit to work with me so I could change if my clothes got wrinkled(皱的).” Today David wears casual clothes—khaki pants and a sports shirt—to the office. He hardly ever wears a necktie.“I'm working harder than ever,” David says,“and I need to feel comfortable.”
More and more companies are allowing their office workers to wear casual clothes to work. In the United States, the changes from formal to casual office wear have been slow. In the early 1990s,many companies allowed their workers to wear casual clothes on Friday(but only on Friday).This became known as “dress-down Friday” or “casual Friday”.“What started out as an extra one-day-a-week benefit for workers has really become an everyday thing,” said business adviser Maisly Jones.
Why have so many companies started allowing their workers to wear casual clothes? One reason is that it's easier for a company to attract new workers if it has a casual dress code. “A lot of young people don't want to dress up for work,” says the owner of a software company,“so it's hard to hire people if you have a conservative dress code.” Another reason is that people seem happier and more productive when they are wearing comfortable clothes. In a study made by Levi Strauss and Company, 85 percent of employers said that casual dress has a side effect on work. Supporters of casual office wear also say that a casual dress code helps them save money. “Suits are expensive, if you have to wear one every day,” one person said.“For the same amount of money, you can buy a lot more casual clothes.”David Smith refers to himself as having been “a clothes addict” because _______.
| A．he often wore khaki pants and a sports shirt |
| B．he couldn't stand a clean appearance |
| C．he wanted his clothes to look tidy and clean all the time |
| D．he didn't want to spend much money on clothes |
David Smith wears casual clothes now, because _______.
| A．they make him feel at ease when working |
| B．he cannot afford to buy expensive clothes |
| C．he looks handsome in casual clothes |
| D．he no longer works for any company |
According to this passage, which of the following is FALSE?
| A．Many workers don't like a conservative dress code. |
| B．Comfortable clothes make workers more productive. |
| C．A casual clothes code is welcomed by young workers. |
| D．All the employers in the U.S. are for casual office wear. |
According to this passage, which of the following is TRUE?
| A．Company workers started to dress down about twenty years ago. |
| B．Dress-down has become an everyday phenomenon since the early 1990s. |
| C．“Dress-down Friday” was first given as a favor from employers. |
| D．Many workers want to wear casual clothes to impress people. |
Many college students have after-school jobs. Students both go to school and have a job at the same time. Every student has his or her own reason for having an after-school job. The most common reason is to help pay for college. In the US, going to a college or university may be very expensive. Not only must students pay for classes, they must also pay for a place to live, food, and other expenses. Buying books for classes can also be very expensive. Students spend as much as five hundred US dollars on books. Many parents do not have enough money to pay all of these expenses, so the students must get an after-school job to help pay for his or her education.
Other students have after-school jobs not to pay for college, but to make and save a little money. Even after all of the school fees are paid, students often have many other expenses. Also, students like to go out and have fun. They may want to do anything from shopping to going to music concerts, to going out to bars and drinking with friends. Though it can be a lot of fun to do all of these things, you can not participate if you do not have money. Because of this, many students try to find jobs so that they can have fun as well as study.
Some students get after-school jobs simply to gain more experience. If a student has neverworked before, he or she can have the opportunity to have his or her first job. If a student is interested in banking, he or she may spend a few hours every week working at a local bank. If a student is interested in working in a library after he or she graduates from college,the student can often find a job at the college library. There are many job opportunities for students who are interested in gaining experience in the area his or her choice.
Though some people feel that after-school jobs take away from a student's time to do his or her homework, working is a great learning experience that happens outside of the classroom,and can provide many new opportunities for the students.After reading the passage, we know that, besides paying for college education, American students have after-class jobs to _______.
| A．make or save a little money and gain some experience |
| B．simply earn some money |
| C．support his or her family |
| D．have fun only |
In the third paragraph the purpose of giving examples is _______.
| A．to say that they have no choice but to do some jobs in college |
| B．to show that the students are interested in working in banks and libraries |
| C．to show that working in a bank or a library is the best way to earn money |
| D．to explain how the students gain experience from after-school jobs |
The best title for this passage is _______.
| A．To Get an After-school Job for Fun |
| B．Getting an After-school Job for Your Education |
| C．After-school Jobs |
| D．Experience Is Very Important for Your Job |
Some kids can't sit still for long. They have a hard time paying attention to just one thing. They're easily distracted(分神).They can get very impatient. They hate standing in line or waiting for their turn in a game or activity. They get bored pretty fast. They may also be impulsive—saying the first thing that comes to mind or interrupting someone else who's talking.
For certain kids, this problem is so severe(严重) that doctors have a name for it: attention deficit hyperactivity disorder, or ADHD. Perhaps as many as 1 out of every 20 kids under the age of 18 have characteristics of ADHD. Often, these kids have trouble getting through school and face other difficulties later in life.
Rizzo started developing the Virtual Classroom in 1999.He wanted to see if he could use it as a tool for testing and treating kids who have attention disorders.
To diagnose(诊断) ADHD, doctors typically test patients by giving them tasks that require attention. As part of one classic test, you watch letters flashed on a computer screen. Every time you see the letter “A” followed by the letter “X”,you have to press the space bar. If you're paying close attention, you'll register all the times this combination occurs. If not, you'll miss some.
The Virtual Classroom makes these tests more efficient, Rizzo says. In one experiment, he gave a group of kids the classic “A-X” test. Instead of looking at a computer screen in a doctor's office, though, the kids wore headsets that made it look like they were taking the test in a classroom.
“Basically what we found,”Rizzo says,“is that, in 20 minutes of testing with virtual reality,we replicated(复制) a finding that usually requires a couple hours of standard testing with computer screens in the psychologist's office.”The first paragraph mainly tells us _______.
| A．how to find a patient with ADHD |
| B．the behavior of some kids with ADHD |
| C．kids with ADHD cannot sit still for a long time |
| D．kids with ADHD are easily distracted |
Perhaps as many as _______ kids have characteristics of ADHD.
A. one out of every twenty kids
B. five percent kids less than 18 years old
C. one out of twenty kids at the age of 18
D. five percent kids more than age of 18 In the experiment, patients need to press the space bar, when _______.
| A．see letters A following X | B．first see A then see B |
| C．see letter X and A | D．see letters A followed by X |
The main idea of the last paragraph is _______.
| A．in virtual classroom, we finish the test in 20 minutes |
| B．the standard test with computer screen usually costs several hours |
| C．the experiment is easy to do |
| D．the result of the experiment |
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