by accident(=by chance, accidentally)偶然地,意外. without accident 安全地, He did it whether by accident or design. 查看更多

 

题目列表(包括答案和解析)

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

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.We were all waiting for you .You _____for the seaside by yourself without leaving a message.

   A. mustn’t leave     B. shouldn’t have left   C. couldn’t have left  D. needn’t leave

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Mary Cassatt is one of the first great women American painters. At first her father did not want her to become an artist. But she followed her dreams and became an artist.She was born on

May 22, 1844, and lived in Europe for several years as a child.

   Her family returned to the United States and, at age 16, Mary attended the Pennsylvania Academy of Fine Arts. Four years later she decided she couldn't learn anything fresh and practical in Philadelphia, so she returned to Europe. There she studied the skills of the masters in Rome, Seville, Antwerp, and Paris.

   Mary received the chance of a lifetime at the age of 33 when the famous French painter, Edgar Degas, asked her to join a group of painters that included now-famous artists like Manet and Renoir. Their style of painting is called Impressionism. They used primary colors and short brush strokes(笔画) in their work. They recognized Mary 's spirit and powerful talent and invited her to exhibit in the Impressionist art shows.

   Mary painted what she saw: gardens, and paintings of persons , especially of mothers and children involved in everyday living. One of her paintings, "Young Mother and Two Children," was given to the White House in 1954 where it hangs today.

   Mary never married and, in 1877, her parents and sister moved to Europe to join her. Mary devoted much of her time to them for the next 18 years to their care. Mary painted until 1914 when her failing eyesight made it impossible to continue. She spent the later years of her life in Paris. She died in 1926 at the age of 82. Unfortunately,all her life, she refused to accept students.

Mary left Pennsylvania for Europe at age 20 mainly because_____.

   A. she wanted to learn another style of paintings

   B. she didn’t learn anything in Pennsylvania

   C. her desire for the learning wasn’t satisfied well

   D. her father didin’t want her to learn painting again

Which year was the most critical to her career and life?

   A. 1860   B. 1864   C. 1877    D. 1914

Which of the statements about Mary Cassatt is supported by the passage?

   A. Her father had a decisive effect on her painting

   B. Her painting featured scenes of everyday living

   C. She used various colors and long lines in her works

   D. She studied the paintings of the masters in U.S.A

Mary Cassatt stopping painting because of_____.

   A. her poor eyesight     B. her old age     C.lack of interest   D. her family

It can be inferred from the passage that _____.

   A. during the last ten year of life, she painted nothing.

   B. the paintings of Edgar Degas belong to realism

   C. her works were controversial though highly recognized

   D. her students showed great respect for her

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阅读下面一则广告,按照要求完成写作任务。

EIL International English Summer Camp

Volunteer Wanted

   EIL was founded in Britain in 1936 with the fundamental aim of international understanding “Learn to live together by living together”.

Requirements: Over 16; good knowledge of English; outgoing; working well with children

between 7-12

Activities: Language study, outdoor recreation and travel

Campers: Students from different countries

Camp site: Mount Wuyi, Fujian

Time: July 26-August 9

Application deadline: July 15. 2008

      If interested, please e-mail to info@eiuk.org

[写作内容]

   假设你是李华,这则广告引起了你的兴趣,请用英文写一封自荐信。要求如下:

对夏令营主题的理解;

根据招聘要求自我介绍;

参加夏令营的目的。

注意:1. 信的开头和结尾已为你写好,不计入总词数;

2.词数100左右。

Dear sir,

I’m Li Hua from Fujian.

I am looking forward to your early reply.

                                                       Sincerely yours,

                                                           Li Hua

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Compared with the previous week, air quality in Shanghai became worse last week , according to the latest report from the Shanghai Environment Monitoring Centre.

       The average air pollution index (API) for sulphur dioxide (SO2) remain almost unchanged from the previous week, but the APIs for nitrogen oxide (NOx) and total suspended (悬浮) particles (TSP) rose by 35 and 27 percent.

       The overall quality still belonged to class 2 category.Nitrogen oxide, caused mainly by vehicle exhaust and burning of cooking gas, was still the major pollutant of the week.

       The Shanghai Environmental Monitoring Centre operates six automatic air monitors in the city’s Putuo, Yangpu, Luwan, Hongkou, Jing’an and Xuhui districts.

 

      

Judging from the chart, on which day was the air quality the worst?

       A.October 13.   B.October 14.   C.October 17.   D.October 18.

Which of the following can be used to describe the air quality of the week?

       A.Good.           B.Seriously polluted.

       C.Excellent.             D.Slightly polluted.

Six automatic air monitors are operated in the city except ________.

       A.Putuo District

       B.Xuhui District

       C.Chang’an District

       D.Hongkou District

In shanghai, nitrogen oxide mainly comes from ________.

       A.the burning natural gas

       B.the burning cooking gas

       C.the burning coal

       D.dust raised by vehicles

This passage is obviously taken from ________.

       A.a magazine about air pollution

       B.a scientific report from TV

       C.the weather column in a newspaper

       D.the traveling guide to Shanghai

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