题目内容

The detective finally discovered the lonely house, whose door was half-open, _______ there for a while, and then entered it, only _______ the man he was looking for already dead.

[　　]

A．to stand; finding
B．stand; finding
C．stood; to find
D．standing; to find

答案：C
解析：

前者用过去时，表示连续做的第二个动作；后者用动词不定式，表示意外的结果。


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Plants can’t communicate by moving or making sounds, as most animals do. Instead, plants Produce volatile compounds, chemicals that easily change from a liquid to a gas. A flower’s sweet smell, for example, comes from volatile compounds that the plant produces to attract insects such as Bugs and bees.

Plants can also detect volatile compounds produced by other plants. A tree under attack by Hungry insets, for instance, may give off volatile compounds that let other trees know about the Attack. In response, the other trees may send off chemicals to keep the bugs away ——or even  Chemicals that attract the bugs’ natural enemies.

Now scientists have created a quick way to understand what plants are saying: a chemical Sensor（传感器）called an electronic nose. The “e-nose” can tell compounds that crop plants make When they’re attacked Scientists say the e-nose could help quickly detect whether plants are being Eaten by insects. But today the only way to detect such insects is to visually inspect individual Plants. This is a challenging task for managers of greenhouses, enclosed gardens than can house Thousands of plants.

The research team worked with an e-nose than recognizes volatile compounds. Inside the device, 13 sensors chemically react with volatile compounds Based on these interactions, the e-nose gives off electronic signals that the scientists analyze using computer software.

To test the nose, the team presented it with healthy leaves from cucumber, pepper and tomato plants, all common greenhouse crops. Then scientists collected samples of air around damaged leaves from each type of crop, These plants had been damaged by insects, or by scientists who made holes in the leaves with a hole punch（打孔器）. The e-nose, it turns out, could identify healthy cucumber, pepper and tomato plants based on The volatile compounds they produce, It could also identify tomato leaves that had been damaged. But even more impressive, the device could tell which type of damage ---- by insects or with a hole Punch ---- had been done to the tomato leaves.

With some fine-tuning, a device like the e-nose could one day be used in greenhouses to quickly spot harmful bugs, the researchers say. A device like this could also be used to identify fruits that are perfectly ripe and ready to pick and eat, says Natalia Dudareva, a biochemist at Purdue University in West Lafayette, Ind. who studies smells of flowers and plants. Hopefully, scientists believe, the device could bring large benefits to greenhouse managers in the near future.

We learn from the text that plants communicate with each other by____.

A. making some sounds        B. waving their leaves

C. producing some chemicals   D. sending out electronic signals

What did the scientists do to find out if the e-nose worked?

A. They presented it with all common crops.

B. They fixed 13 sensors inside the device.

C. They collected different damaged leaves.

D. They made tests on damaged and healthy leaves.

According to the writer, the most amazing thing about the e-nose is that it can___.

A. pick out ripe fruits

B. spot the insects quickly

C. distinguish different damages to the leaves

D. recognize unhealthy tomato leaves

We can infer from the last paragraph that the e-nose_____.

A. is unable to tell the smell of flowers

B. is not yet used in greenhouses

C. is designed by scientists at Purdue

D. is helpful in killing harmful insects

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项。

     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.    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.        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.      When a suspect leaves finger-prints behind at the scene of a crime, they are difficult to detect with the naked eye.

        Some of the marks found are incomplete but identification is possible if a print of a quarter of an inch square can be obtained.

A. Special techniques are used to "develop" them.

B. A fingerprint is an impression of the friction ridges of all part of the finger.

C. It is only when the inner skin is injured that the arrangement will be destroyed.

D. With special methods, identification can be achieved successfully within a short time.

E. This is called a latent print.

F. His finger-prints can prove who he is even if his appearance has been changed by age or accident.

G. Every human being has a unique arrangement of the skin on his fingers and this arrangement is unchangeable.

People are overweight for many reasons, the most important one of which is that they eat the wrong foods, get the wrong types of calories per meal, and they also eat meals at the wrong time each day. Food is more powerful than any weight loss pill, because the food that you eat can either make you thin or fat. This is true because your body is like an engine, and it only needs certain foods at certain intervals(间隔)each day.
Low-calorie Diets Do Not Work 
The reason people cannot lose weight by starving themselves is that their metabolism(新陈代谢)will detect any major drop in calories and it will then adjust(调整)itself by burning fewer calories each day. That is the reason why you can eat 1,000 calories per day and not lose any weight, while your friends can eat 2, 500 calories per day and not gain any weight.
Low-fat Diets Do Not Work
Many people in today’s society are buying mostly low- fat or non-fat food at the grocery store. Everybody knows how much fat is inside the food they buy. However, people are getting fatter than ever before by doing this. They are not losing weight by changing to this low-fat lifestyle.
Losing weight has nothing to do with these things. One of the most important things you can do to control your weight is to eat the proper foods, such as fruit and vegetables, eat them at the right time, and exercise every day. If people make this a habit, they will lose weight.
【小题1】What is the main reason why people are overweight according to the author?

A．They eat the wrong foods at the wrong time.
B．They eat food with lots of calories.
C．They don’t take any weight loss pills.
D．They burn many calories every day.
【小题2】The article is written in order to _______.
A．tell readers not to buy low-fat or non-fat food
B．tell readers how to lose weight
C．tell readers about an important scientific discovery
D．call on people to lose weight and stay healthy
【小题3】To realize the aim of your weight loss plan, you should ________.
a. do exercise every day       b. eat meals at the right time
c. eat fruits and vegetables     d. eat low-fat or sweet food
e. eat the proper foods at each meal
A．a, b, c, dB．a, b, d, e
C．a, c, d, e D．a, b, c, e

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?

A．Bacteria. B．A high-tech scanner.C．A camera D．Food safety.
【小题2】E. coli bacteria ______.
A．broke out all over the world B．comes from soil or animal waste
C．is extremely harmful to health D．does not cause illness
【小题3】The high-tech scanner ______.
A．can help to sort out different fruits
B．make the produce appeal to shoppers
C．can only capture images of the whole apple
D．can identify the presence of contaminants
【小题4】What can be inferred from the text?
A．The scanner needs to be improved.
B．The scanner will be available in the next several years.
C．Moon Kim is unwilling to develop the scanner.
D．The scanner is connected to a sorting machine.

At a laboratory in Germany ,volunteers slide into a machine and perform simple tasks, such as deciding whether to add or subtract two numbers , or choosing which of two buttons to press.

They have no idea that scientists in the next room are trying to read their minds-using a brain scan to figure out their intention before it is turned into action.

In the past ,scientists had been able to detect decisions about making physical movements before those movements appeared .But researchers at Berlin's Bernstein Center for Computational Neuroscience claim they have now , for the first time ,identified people's decisions about how they would later do a high-level mental activity-in this case ,adding versus subtracting.

While still in its initial stages ,the techniques may eventually have wide-ranging implications for everything from criminal questioning to airline security checks.

The research,which began in July 2005,has been of limited scope:only 21 people have been tested so far.And the 71 percent accuracy rate is only about 20 percent more successful than random selection.

Still ,the research conducted at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig ,about 150 kilometers southwest of Berlin ,has been generating strong interest in the scientific community.

In one study ,participants were told to decide whether to add or subtract two numbers a few seconds before the numbers were flashed on a screen . Meanwhile ,a computer captured images of their brain waves to predict the subject's decision-with one pattern suggesting addition, and another subtraction.

The team ,headed by Haynes ,began its research by trying to identify which part of the mind was storing intentions. They discovered it was found in the prefrontal cortex region by scanning the brain to look for bursts of activity when subjects were given choices.

Then they went about studying which type of patterns were associated with different intentions.

"If you knew which thought signatures to look for ,you could theoretically predict in more detail what people were going to do in the future," said Haynes.

75.Which of the following is true about the experiment at the laboratory?

A.The volunteers are asked to perform very complicated tasks.

B.Everything was explained to the volunteers before the experiment.

C.The volunteers cannot see the scientists while performing the tasks.

D.The volunteers started the experiment by pressing one of the two buttons.

76.Which of the following demonstrates the major breakthrough made by the German scientists?

A.By studying the subjects' brain waves , they know what physical movements they'll make.

B.By studying the subjects' brain waves, they know what mental task they'll perform.

C.By studying criminals' brain waves ,they can help find out whether they are lying or not.

D.By studying passengers' brain waves ,they can help find out who intends to make trouble.

77.In the research which began in July 2005 only______subjects' brains were scanned and the accuracy rate was______.

A.21; 20%      B.71;20%       C.21;71%       D.20;71%

78.The group of scientists in Leiqzig were doing______what the group in Berlin were doing.

A.similar research to                  B.better research than

C.completely different things from        D.a less satisfactory job than

79.The term thought signatures in the last paragraph refers to______.

A.the subjects' intentions       B.the subjects' physical movements

C.parts of the human brain    D.the human brain wave patterns

80.From the information in the passage, it can be concluded that in the future______.

A.the intentions of people can be predicted accurately

B.it's impossible to predict accurately the intentions of people

C.no one in the world will dare to tell lies to other people

D.everyone will easily know what others are thinking about

 

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