8. It is a kind of economy which extracts resources, uses them only once or twice, and then throws them away.

A．It is a powerful and fast-acting drug.

B．It causes the familiar yellow and brown stain.

C．Increased heart rate, and blood disease.

D．Increased heart rate, and blood pressure.

SWOT analysis is a kind of risk identification method．If the project team chose me WT strategy, they should（ ）． A．overcome the weakness and reduce the threat B．make full use of the advantage and reduce the threat C．overcome the weakness and catch the opportunity D．make full use of the advantage and catch the opportunity

It is natural to assume that as the Sun grows older, and uses up its hydrogen fuel-which it is now doing at the spanking rate of half a billion tons a second-it will become steadily colder and redder.

Spare a Kidney?

It is no longer unusual for a spouse or relative to donate a kidney to a loved one, but the number of Americans who have given a kidney to a friend, a co-worker or even a complete stranger has risen sharply from 68 in 1994 to 176 in 1998.

There are many reasons. First, it's possible to live a normal life with only one kidney. (The remaining kidney enlarges to make up most of the difference.) In addition a kidney from a live donor lasts longer than a kidney taken from someone who has died suddenly. But the biggest change in the past few years is that transplant surgeons have started using laparoscopic techniques to remove the donor kidney through a much smaller incision, and this can cut recovery time for the donor from six weeks to four weeks.

Just because you do something, however, it doesn't mean you should. Donating a kidney means undergoing an operation that carries some risk. You could argue that you may be helping to save a life, but you certainly can't pretend that you're better off with one kidney instead of two.

So, what are the risks? "As with any major operation, there is a chance of dying, of reoperation due to bleeding, of infection, of vein clots in the legs or a hernia at the incision," says Dr. Arthur Matas, director of the renal-transplant program at the university of Minnesota Medical Center in Minneapolis. Even laparoscopy, a relatively new technique for kidney donation, is not risk-free. Doctors estimate that chances of dying from the procedure are about 3 in 10,000.

There's no money to be made; selling an organ is illegal. But the recipient's insurance normally covers your operation and immediate aftercare. Your costs can include hotel bills, lost pay during recovery or possible future disability.

Although transplant centers must evaluate any potential donor's suitability, it never hurts to have an independent opinion. The most common contraindications are heart disease, diabetes and high blood pressure.

Never let anyone, not even a close relative, pressure you into giving up an organ--no matter if you're healthy. "There's often the feeling that you're not a good friend, father, mother if you don't do this," says Arthus Caplan, director of the University of Pennsylvania's center for Bioethics. Some transplant centers will invent a "medical problem" on behalf of those who are reluctant to donate but feel they can't say no.

From 1994 to 1998 the number of Americans who had donated a kidney reached 244.

A. Right

B. Wrong

C. Not mentioned

In the 1950s, the pioneers of artificial intelligence (AI) predicted that, by the end of this century, computers would be conversing with us at work and robots would be performing our housework. But as useful as computers are, they're nowhere close to achieving anything remotely resembling these early aspirations for humanlike behavior. Never mind something as complex as conversation: the most powerful computers struggle to reliably recognize the shape of an object, the most elementary of tasks for a ten-month-old kid.

A growing group of AI researchers think they know where the field went wrong. The problem, the scientists say, is that AI has been trying to separate the highest, most abstract levels of thought, like language and mathematics, and to duplicate them with logical, step-by-step programs. A new movement in AI, on the other hand, takes a closer look at the more roundabout way in which nature came up with intelligence. Many of these researchers study evolution and natural adaptation instead of formal logic and conventional computer programs. Rather than digital computers and transistors, some want to work with brain cells and proteins. The results of these early efforts are as promising as they are peculiar, and the new nature-based AI movement is slowly but surely moving to the forefront of the field.

Imitating the brain's neural network is a huge step in the right direction, says computer scientist and biophysicist Michael Conrad, but it still misses an important aspect of natural intelligence. "People tend to treat the brain as if it were made up of color-coded transistors", he explains, "but it's not simply a clever network of switches. There are lots of important things going on inside the brain cells themselves. " Specifically, Conrad believes that many of the brain's capabilities stem from the pattern recognition proficiency of the individual molecules that make up each brain cell. The best way to build an artificially intelligent device, he claims, would be to build it around the same sort of molecular skills.

Right now, the option that conventional computers and software are fundamentally incapable of matching the processes that take place in the brain remains controversial. But if it proves true, then the efforts of Conrad and his fellow AI rebels could turn out to be the only game in town.

The author says that the powerful computers of today ______.

A．are capable of reliably recognizing the shape of an object

B．are close to exhibiting humanlike behavior

C．are not very different in their performance from those of the 50's

D．still cannot communicate with people in a human language

In the 1950s, the pioneers of artificial intelligence (Al) predicted that, by the end of this century, computers would be conversing with us at work and robots would be performing our housework. But as useful as computers are, they're nowhere close to achieving anything remotely resembling these early aspirations for human like behavior. Never mind something as complex as conversation: the most powerful computers struggle to reliably recognize the shape of an object, the most elementary of tasks for a ten-month-old kid.

A growing group of Al researchers think they know where the field went wrong. The problem, the scientists say, is that AI has been trying to separate the highest, most abstract levels -of thought, like language and mathematics, and to duplicate them with logical, step-by-step programs. A new movement in AI, on the other hand, takes a closer look at the more roundabout way in which nature came up with intelligence. Many of these researchers study evolution and natural adaptation instead of formal logic and conventional computer programs, Rather than digital computers and transistors, some want to work with brain cells and proteins. The results of these early efforts are as promising as they are peculiar, and the new nature-based: AI movement is slowly but surely moving to the forefront of the field.

Imitating the brain's neural (神经的)network is a huge step in the right direction, says computer scientist and biophysicist Michael Conrad, but it still misses an important aspect of natural intelligence. "People tend to treat the brain as if it were made up of color-coded transistors", he explains, "but it's not simply a clever network of switches. There are lots of important things going on inside the brain cells themselves." Specifically, Conrad believes that many of the brain's capabilities stem from the pattern recognition proficiency of the individual molecules that makeup each brain cell. The best way to build an artificially intelligent device, he claims, would be to build it around the same sort of molecular skills.

Right now, the option that conventional computers and software are fundamentally incapable of matching the processes that take place in the brain remains controversial. But if it proves true, then the efforts of Conrad and his fellow A1 rebels could turn out to be the only game in town.

The author says that the powerful computers of today ______.

A．are capable of reliably recognizing the shape of an object

B．are close to exhibiting humanlike behavior

C．are not very different in their performance from those of the 50's

D．still cannot communicate with people in a human language

1. Mnemonics are tools which can help you to improve your memory. 2. The fundamental principle of mnemonics is to make full use of the best functions of the brain to store information. 3. Information we have to remember is almost always presented in different ways. (Unfortunately information we have to remember is almost always presented in only one way — as words printed on a page.) 4. We can do four things to form striking images, which will help to make our mnemonics more effective. 5. There is one basic principle in the use of mnemonics. (There are three fundamental principles underlying the use of mnemonics.) 6. Association is what we use to create and strengthen imagination. (Imagination is what you use to create and strengthen the associations needed to create effective mnemonics.) 7. You can choose any imagery to use in your mnemonics as long as it is helpful. 8. You can create associations by linking things using the same stimuli.