How can you find out what is going on inside a person’s
body without opening the patient’s body up? Regular X rays can show a lot. CAT scans can show even more. They can g
ive a complete view of body organs.
What is a CAT scan? CAT stands for a kind of machine. It is a special X-ray machine that gets a 360-degree picture of a small area of a patient’s body.
Doctors use X rays to study and determine diseases and injuries within the body, X rays can find a foreign object inside the body or take pictures of some inside organs to be X-rayed.
A CAT scanner, however, uses a group of X rays to give a cross-sectional（横截面）view of a specific part of the body. A fine group of X rays is scann
ed across the body and around the patient from many different directions. A computer studies the information from each direction and produces a clear cross-sectional picture on a screen. This picture is then photographed for later use. Several cross sections, taken one after another, can give clear “photos” of the entire body or of any body organs. The latest CAT scanners can even give clear pictures of active, moving organs, just as a fast-action camera can “s
top the action”, giving clear pictures of what appears unclear to the eye. And because of the 360-degree pictures, CAT scans show clear and complete views of organs in a manner that was once only shown during operation or examination of a dead patient.
Frequent appearance before X rays can cause skin burns, cancer or other damage to the body. Yet CAT scans actually don’t cause the patient to more radiation than regular X rays do. CAT scans can also be done without getting something harmful into the patient, so they are less risky than regular X rays.
CAT scans provide exact, detailed information. They can quickly find such a thing as bleeding inside the brain. They are helping to save lives.What is NOT true of a CAT scan?
| A．It is safer than regular X rays. |
| B．It makes use of computer techniques. |
| C．It can stop the action of an organ for a short time. |
| D．It gives clear pictures of active, moving body parts. |
The underlined words “a foreign object”（Para 3）most probably refer to .
| A．a badly injured part inside the body |
| B．a new thing that is unknown to the doctor |
| C．a strange organ that has grown in the body |
| D．an object that gets inside the body by chance |
What is the special use of the latest CAT scanners?
| A．It provides clear photos of moving organs. |
| B．It can take 3-dimension（三维）pictures of inside organs. |
| C．It won’t cause serious skin burns, cancer or other damage to the body. |
| D．It helps to find out what is going on inside a person’s body without opening it up. |
We can infer from this passage that .
| A．patients in front of CAT may suffer from a bit of radiation |
| B．doctors need no opening-up of the body with CAT scanners |
| C．CAT scanners are more expensive than regular X-ray machines |
| D．CAT scanners can take photos of either the whole body or a part of it |
The best title of this passage might be .
| A．the Newest Medical Invention |
| B．New X-ray Machine to Save Lives |
| C．How to Avoid the Damage of X Rays |
| D．Advantages and Disadvantages of CAT Scanners |
If English means endless new words, difficult grammar and sometimes strange pronunciation, you are wrong. Haven't you noticed that you have become smarter since you started to learn a language?
According to a new study by a British university, learning a second language can lead to an increase in your brain power. Researchers found that learning other languages changes grey matter. This is the area of the brain which processes information. It is similar to the way that exercise builds muscles.
The study also found the effect is greater, the younger people learn a second language.
A team led by Dr Andrea Mechelli, from University College London, took a group of Britons who only spoke English. They were compared with a group of "early bilinguals" who had learnt a second language before the age of five, as well as a number of later learners.
Scans showed that grey matter density (密度) in the brain was greater in bilinguals than in people without a second language. But the longer a person waited before mastering a new language, the smaller the difference.
"Our findings suggest that the structure of the brain is changed by the experience of learning a second language," said the scientists.
It means that the change itself increases the ability to learn.
Professor Dylan Vaughan Jones of the University of Wales, has researched the link between bilingualism and maths skills. "Having two languages gives you two windows on the world and makes the brain more flexible (灵活的),"he said. "You are actually going beyond language and have a better understanding of different ideas."
The findings were matched in a study of native Italian speakers who had learned English as a second language between the ages of two and 34. Reading, writing, and comprehension were all tested. The results showed that the younger they started to learn, the better. "Studying a language means you get an entrance to another world," explained the scientists.
The underlined word “bilingual'’ probably means ______.
| A．a researcher on language learning |
| B．a person who is good at learning foreign languages |
| C．a person who can speak two languages |
| D．an active language learner |
I remember the first time that I was extremely happy. I was about 8 years old when for the first time, there was a computer in the classroom. I remember that my teacher allowed each student to take turns to play various educational games on the computer. One day, I found the source code(编码) for one of these games. Without knowing or being taught any programming language, I was able to figure out some of the BASIC code. I just gave myself an infinite number of lives in the game, so I could continue playing it forever. This was also my first introduction to algebra, and I didn't even know it at the time. This was a decisive moment in my life. I was quite excited because of what I was learning and what I was able to do. As a result, I was enthusiastic for the rest of my life about self learning and computers, and I was quite happy doing them too.
I've noticed that people who are truly content with life are enthusiastic about what they do. This enthusiasm, along with good health, is the key to being happy. It also leads to self-confidence and content in life too. It may also lead to success, wealth, and achievements.
Success, wealth, or achievements can also bring some people happiness, yet I know plenty of rich people who are unhappy. I know many people with successful businesses that are not happy with what they are doing. I know people who continuously buy themselves new toys, such as cars, computers, and televisions, yet never seem content for too long. Please remember, happiness is the journey of life, not the destination.
The underlined word "infinite" means_______
| A．big | B．limitless |
| C．normal | D．small |
Planet Earth would be a scary place for humans if dinosaurs still ruled the world.
Though there are still some traces of life from the Jurassic Period, the Age of Dinosaurs more than 65 million years ago.
This mass extinction is believed to be the result of an asteriod（小行星）hitting Earth. A new report by the journal Biological Reviews called " The Extinction of Dinosaurs” concludes that this impact was, indeed, the cause of the dinosaurs’demise. But the space blast(爆炸) wasn't the only reason these creatures aren't still around today.
Dinosaurs need food to survive. Meat-eating monsters like the Tyrannosaurus Rex(霸王龙) were at the top of the food chain, and fed off plant eaters like the horned Triceratops (三角恐龙). These herbivores (食草动物) were decreasing in population after the asteroid hit Earth, which left the meat-eating species less food to survive on. “In any ecosystem where you remove links to key species, that community has problems," Richard Butler, one of the review's authors, told National Ceographic.
While the herbivore population was going down, Earth's temperatures were rising when volcanoes erupted. Hot vapors and gases began wiping out some of the dinosaur population and weakening the survivors.
These changes made the asteroid's impact especially powerful. It caused more volcanoes to erupt, heated up Earth's atmosphere, and led to a sharp drop in the level of oxygen in the oceans.
With the dinosaurs gone, mammals(哺乳动物) began to evolve into bigger and more diverse species. Many animals we see today, like birds, sharks, and even some cats and dogs, appeared after the asteroid hit Earth. But none rule Earth quite like the dinosaurs did..
Which of the following words can replace the underlined word“demise” in Paragraph 2?
| A．Death. | B．Evolvement. |
| C．Presence. | D．Decrease. |
You may not pay much attention to your daily elevator ride. Many of us use a lift several times during the day without really thinking about it. But Lee Gray, PhD, of the University of North Carolina, US, has made it his business to examine this overlooked form of public transport. He is known as the “Elevator Guy”.
“The lift becomes this interesting social space where etiquette（礼仪）is sort of strange,” Gray told the BBC. “They are socially very interesting but often very awkward places.”
We walk in and usually turn around to face the door. If someone else comes in, we may have to move. And here, according to Gray, liftusers unthinkingly go through a set pattern of movements. He told the BBC what he had observed.
He explained that when you are the only one inside a lift, you can do whatever you want – it’s your own little box.
If there are two of you, you go into different corners, standing diagonally（对角线地）across from each other to create distance.
When a third person enters, you will unconsciously form a triangle. And when there is a fourth person it becomes a square, with someone in every corner. A fifth person is probably going to have to stand in the middle.
New entrants to the lift will need to size up the situation when the doors slide open and then act decisively. Once in, for most people the rule is simple – look down, or look at your phone.
Why are we so awkward in lifts?
“You don’t have enough space,” Professor Babette Renneberg, a clinical psychologist at the Free University of Berlin, told the BBC. “Usually when we meet other people we have about an arm’s length of distance between us. And that’s not possible in most elevators.”
In such a small, enclosed space it becomes very important to act in a way that cannot be construed（理解）as threatening or strange. “The easiest way to do this is to avoid eye contact,” she said.
The underlined phrase “size up” in Paragraph 7 is closest in meaning to _______.
A. judge B. ignore
C. put up with D. make the best of
Scientists today are making greater effort to study ocean currents (洋流) . Most do it using satellites and other high-tech equipment. However, ocean expert Curtis Ebbesmeyer does it in a special way -- by studying movements of random floating garbage. A scientist with many years’ experience, he started this type of research in the early 1990s when he heard about hundreds of athletic shoes washing up on the shores of the northwest coast of the United States. There were so many shoes that people were setting up swap meets to try and match left and right shoes to sell or wear.
Ebbesmeyer found out in his researches that the shoes — about 60,000 in total — fell into the ocean in a shipping accident. He phoned the shoe company and asked if they wanted the shoes back. As expected, the company told him that they didn't. Ebbesmeyer realized this could be a great experiment. If he learned when and where the shoes went into the water and tracked where they landed, he could learn a lot about the patterns of ocean currents.
The Pacific Northwest is one of the world's best areas for beachcombing(海滩搜寻) because winds and currents join here, and as a result, there is a group of serious beachcombers in the area. Ebbesmeyer got to know a lot of them and asked for their help in collecting information about where the shoes landed. In a year he collected reliable information on 1, 600 shoes. With this data, he and a colleague were able to test and improve a computer program designed to model ocean currents, and publish the findings of their study.
As the result of his work, Ebbesmeyer has become known as the scientist to call with questions about any unusual objects found floating in the ocean. He has even started an association of beachcombers and ocean experts, with 500 subscribers from West Africa to New Zealand. They have recorded all lost objects ranging from potatoes to golf gloves.
The underlined phrase swap meets in Paragraph 1 is closest in meaning to ______________.
| A．fitting rooms |
| B．trading fairs |
| C．business talks |
| D．group meetings |