How much do you know about A.I. (Artificial Intelligence)?Artificial means‘man-made', and intelligence means‘the ability to learn. understand and think about things'. A.I. is about making machines think, talk, do and see. A.I. is used in many fields from、playing games to helping doctors. Many machines around us work very well because they work with the help of A.I. Man has always dreamed of building‘thinking machines'. In 1770, Wolfgand Kempelen(1 734—1804)built a wooden robot called Turk that was able to play chess(SUR). It played very well and even beat some of the top chess players of the time! Later it was found that Turk was not real. Inside the box machine was a chess player.
John McCarthy(1927—)is thought as the‘Father'of A.I. He invented the word‘A.I.'and the LISP computer programming language that many A.I. developers use today. How does A.I. work?
A.I. uses ideas from many fields:

    Could smells affect your lifespan? Female fruit flies (果蝇) without the ability to smell food live longer than other fruit flies．The sense of smell may be connected to the cellular ageing (细胞老化) process in many other living things  even people．Such connection has recently been found in both worms and flies．For example, scientists found that removing fruit flies' ability to smell made them live nearly 20 percent longer than flies with a sense of smell．

    They confirmed that food smells were the ones most likely to affect ageing, as nutrition (营养) and lifespan are known to be connected in many living things．To test the idea that food smells affect lifespan, they removed flies' ability to smell carbon dioxide, which is produced by some fly foods．They left the rest of the smelling system．

    This action had no effect on male flies, but the females lived 30 percent longer than normal．Removing the ability to smell CO₂ may stop flies getting information about food availability．This could mean that food is not enough, causing processes that encourage flies to survive．Scientists found that the female flies from stored extra fat and that both males and females immune (免疫) to CO₂ were stronger against the stress than normal flies．It is suggested that females may simply be easily influenced by the smells of CO₂ ．

    Scientists point out that people don't know whether ageing and smell are connected in animals and humans．But they clearly experience physical changes after smelling food．

    In northern China during spring, big sandstorms often make trouble for people. When the sky is dark with sand, buses and cars all move much more slowly. Sometimes, people can't even see for 20 metres.

    Sandstorms usually happen in spring. Big sandstorms happened in more than 10 provinces in northern China last year. More than 70 million people have had problems in those places because of the sandstorms.

    People in southern China don't have to worry about this kind of bad weather. Most of the sand comes from the north of China. In northern China, lots of places have few trees and don't get much rain. People there have been cutting down too many trees. When there aren't many trees, the ground can't keep enough water. Over the years, the ground dries up and turns to sand. When spring comes and the ice melts (融化), the ground becomes looser (更松散的). Strong winds take the loose sand into the sky.

    Sandstorms are bad for people's health. If people take in too much sand, they could cough or have asthma (哮喘).

    Sandstorms also give farmers lots of problems. Sometimes their sheep get lost in the storms and never get back home. The winds also tear down farmers' houses.

    What can you do to stop sandstorms? Here's an idea: Ask your parents to help you plant some trees this spring.

    If you see people cutting down too many trees, tell them about the dangers of sandstorms, and ask your government to stop them from cutting.

    Many people have dogs at home as pets. If a dog is happy, then he may want to meet you or play with you. If he doesn't feel happy, then he would rather stay alone. But dogs can't talk. How can you tell how your dog is feeling? By his body language.

    If your dog's head and back are lowered, his ears are down and his eyes are narrowed, and his tail is between his legs, then he is fearful. You may touch him gently to comfort him. If your dog's ears are up, his eyes are bright, and he wags his tail rapidly (快速地), he is very happy. He may also hold his mouth open more or even pant (气喘) mildly. Then you can go and play with him freely. If he closes his mouth and looks serious as you get closer, then he has changed his mind. It is better to leave him alone until he comes to you. Remember, we are talking about dogs that you know. Be sure a parent is around to allow you to get close to the dog. Get away from strange dogs even if they seem friendly.

    The most important clue (线索) is the mouth. If the dog's mouth is closed, then he is most likely to be not relaxed or happy, and he does not want you to touch or play with him right now.