Europe’s deadly outbreak of a rare form of E. coli bacteria (大肠杆菌) has brought new attention to food safety issues. One of the problems when people get sick from food is that the simplest question is often difficult or even impossible to answer. Just what did the people eat that made them sick?
Of course, one way to avoid these medical mysteries is to keep dangerous organisms out of the food supply. This is easier said than done, but scientists keep looking for new ways.
Scientists in the United States have developed an experimental system that uses a high-tech optical scanner. The system is designed to identify the presence of contaminants(致污物) like soil or animal waste on fresh produce. These can be sources of E. coli. E. coli bacteria naturally live in the intestines(肠) of humans and many animals. Most kinds of E. coli are harmless but some can make people sick.
The new scanner can also show damage and imperfections that might make the produce unappealing to shoppers.
Scientists designed the system at a Department of Agriculture research center in Beltsville, Maryland. Moon Kim of the Agricultural Research Service led the team.
MOON KIM: “We were requested, we were asked, to develop a method to detect contamination in produce. So we started with the apple as the model sample.”
The scanner uses a high-speed camera placed over the conveyer belt that moves the produce along. As the apples move along the belt, the scanner captures images of each piece of fruit.
Moon Kim says the team hopes the system will be available before long.
MOON KIM: “We are targeting for development in commercial plants for the next several years.”
The scanner can direct a sorting machine to separate the bad apples from the good ones. The system is currently able to show the surface of only half the apple as it speeds by. The inventers hope to improve the process so it can show the whole surface.
【小题1】What is the main topic of the text?

Are you a compulsive spender, or do you hold on to your money as long as possible? Are you a bargain hunter? Would you rather use charge accounts than pay cash? Your answers to these questions will reflect your personality. According to psychologists, our individual money habits not only show our beliefs and values, but can also stem from past problems.
Experts in psychology believe that for many people, money is an important symbol of strength and influence. Husbands who complain about their wives’ spending habits may be afraid that they are losing power in their marriage. Wives, on the other hand, may waste huge amounts of money because they are angry at their husbands. In addition, many people consider money a symbol of love. They spend it on their family and friends to express love, or they buy themselves expensive presents because they need love.
People can be addicted to different things — for example, alcohol, drugs, certain foods, or even television. They are compulsive in their addictions, i.e. they must satisfy these needs to feel comfortable. In the same way, according to psychologists, compulsive spenders must spend money. For people who buy on credit, furthermore, charge accounts are even more exciting than money: in other words, they feel that with credit, they can do anything. Their pleasures in spending enormous amounts are actually greater than those they get from the things they buy.
There is even a special psychology of bargain hunting. To save money, of course, most people look for sales, low prices, and discounts. Compulsive bargain hunters, however, often buy things that they don’t need just because they are cheap. They want to believe that they are helping their budgets, but they are really playing an exciting game: when they can buy something for less than other people, they feel that they are winning. Most people, experts claim, have two reasons for their behavior: a good reason for the things that they do and the real reason.
It is not only scientists, of course, who understand the psychology of spending habits, but also business people. Stores, companies, and advertisers use psychology to increase business: they consider people’s needs for love, power, or influence, their basic values, their beliefs and opinions, etc. in their advertising and sales methods.
Psychologists often use a method called “behavior therapy(疗法)” to help individuals solve their personality problems. In the same way, they can help people who feel that they have problems with money: they give them “assignments”. If a person buys something in every store that he enters, for instance, a therapist might teach him self-discipline in this way: on the first day of his therapy, he must go into a store, stay five minutes, and then leave. On the second day, he should stay for ten minutes and try something on. On the third day, he stays for fifteen minutes, asks the salesclerk a question, but does not buy anything. Soon he will learn that nothing bad will happen to him if he doesn’t buy anything, and he can solve the problem of his compulsive buying.  
【小题1】If you use charge accounts, ____.

Foresters are people who work with trees and know a lot about them. Occasionally, foresters have problems, and the foresters in southern Indiana have had many problems.
The foresters were doing an experiment. They wanted to grow walnut (胡桃) trees by planting walnuts in the ground. If they succeeded, the foresters would be able to control the location of the trees. Also, this method would be much cheaper than transplanting or moving nut trees that were grown in plant nurseries (苗圃) . So the foresters planted their walnuts, and that’s when the squirrels (松鼠) started causing trouble. Shortly after the nuts were planted, the squirrels dug them up for tasty snacks (快餐) .
The foresters tried to keep the squirrels away from the walnuts. Mothballs (卫生球) were used as a warning, but they didn’t work. Then, the foresters tried dipping the walnuts in kerosene (煤油) ,  but that didn’t stop the squirrels either. The foresters continue to search for a method that will really work. But until they find one, the squirrels can continue to have their walnut snacks and the foresters will have to transplant trees!
【小题1】Foresters are people who        .

A．Left them alone.	B．Continued to eat them.
C．Hid them in trees	D．Put them into the earth.

A．Mothballs didn’t prove to be a good method of stopping the squirrels from eating the walnuts.

B．The squirrels found the walnuts tasty.

C．The squirrels started eating mothballs instead of walnuts.

D．The forester haven’t found a good way to prevent the squirrels from eating the walnuts.

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
__【小题1】__ Scientists and experts have proved the uniqueness of finger-prints and discovered that no exactly similar pattern is passed on from parents to children, though nobody knows why this is the case.
The ridge(隆起) structure on a person’s fingers does not change with growth and is not affected by surface injuries. Burns, cuts and other damage to the outer part of the skin will be replaced in time by new one, which bears a reproduction of the original pattern. __【小题2】_ Some criminals make use of this fact to remove their own finger-prints but this is a dangerous and rare step to take.
Finger-prints can be made very easily with printer’s ink. They can be recorded easily. __【小题3】_ Because of the simplicity and economy of this system, finger-prints have often been used as a method of solving criminal case. A suspected man may deny a charge but this may be in vain. __【小题4】_ When a suspect leaves finger-prints behind at the scene of a crime, they are difficult to detect(察觉) with the naked eye. __【小题5】__ Some of the marks found are incomplete but identification is possible if a print of a quarter of an inch square can be obtained.

Grown-ups know that people and objects are solid. At the movies, we know that if we reach out to touch Tom Cruise, all we will feel is air. But does a baby have this understanding?

To see whether babies know objects are solid, T. Bower designed a method for projecting an optical illusion of a hanging ball. His plan was to first give babies a real ball, one they could reach out and touch, and then to show them the illusion. If they knew that objects are solid and they reached out for the illusion and found empty air, they could be expected to show surprise in their faces and movements. All the 16 to 24-week-old babies tested were surprised when they reached for the illusion and found that the ball was not there.

Grown-ups also have a sense of object permanence. We know that if we put a box in a room and lock the door, the box will still be there when we come back. But does a baby realize that a ball that rolls under a chair does not disappear and go to never-never land?

Experiments done by Bower suggest that babies develop a sense of object permanence when they are about 18 weeks old. In his experiments, Bower used a toy train that went behind a screen. When 16-week-old and 22-week-old babies watched the toy train disappear behind the left side of the screen, they looked to the right, expecting it to reappear. If the experimenter took the train off the table and lifted the screen, all the babies seemed surprised not to see the train. This seems to show that all the babies had a sense of object permanence. But the second part of the experiment showed that this was not really the case. The researcher substituted a ball for the train when it went behind the screen. The 22-week-old babies seemed surprised and looked back to the left side for the train. But the 16-week-old babies did not seem to notice the switch. Thus, the 16-week-old babies seemed to have a sense of “something permanence, while the 22-week-old babies had a sense of object permanence related to a particular object.

The passage is mainly about _____.

       A. babies’ sense of sight          

       B. effects of experiments on babies

       C. babies’ understanding of objects

       D. different tests on babies’ feelings

In Paragraph 3, “object permanence” means that when out of sight, an object ________.

       A. still exists                        B. keeps its shape

       C. still stays solid                        D. is beyond reach

What did Bower use in his experiments?

       A. A chair.     B. A screen.          C. A film.      D. A box.

Which of the following statements is true?

       A. The babies didn’t have a sense of direction.   

       B. The older babies preferred toy trains to balls.

       C. The younger babies liked looking for missing objects.   

       D. The babies couldn’t tell a ball from its optical illusion.