The tomato juice left a brown ______ on the front of my jacket.

  A.track  B.trace  C.spot   D.point

 

練習冊系列答案
相關(guān)習題

科目:高中英語 來源: 題型:閱讀理解

  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 insects, 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(傳感器) 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 detest 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 that can house thousands of plants.

  The research team worked with an e-nose that 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 the 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 Dudareve, 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.

49. 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

50. 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.

51. 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

52. 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

 

查看答案和解析>>

科目:高中英語 來源:2012-2013學年廣東省陽東廣雅中學陽東一中高一上學期聯(lián)考英語試卷(帶解析) 題型:閱讀理解

So you thought the hamburger was the world’s most popular fast food? After all, McDonald’s Golden Arches span(跨越)the globe(全球). But no, there is another truly universal fast food, the ultimate(極好的)fast food. It’s easy to make, easy to serve, much more varied than the hamburger, can be eaten with the hands and it’s delivered to your front door or served in fancy restaurants. It’s been one of America’s favourite foods for over 50 years. It is, of course, the pizza.
It’s kind of silly to talk about the moment when pizza was “invented”. It changed over the years, but one thing’s for certain—it’s been around for a very long time. The idea of using pieces of flat, round bread as plates came from the Greeks. They called them “plakuntos” and ate them with various simple toppings(配料)such as oil, garlic(大蒜), onions and herbs. The Romans enjoyed eating something similar and called it “picea”. By about 1000 AD in the city of Naples, “picea” had become “pizza” and people were experimenting with more toppings: cheese, ham, anchovies and finally the tomato, brought to Italy from Mexico and Peru in the sixteenth century. Naples became the pizza capital of the world. In 1889, King UmbertoⅠand Queen Margherita heard about pizza and asked to try it. They invited pizza maker, Raffele Esposito, to make it for them. He decided to make the pizza like the Italian flag, so he used red tomatoes, white mozzarella cheese and green basil leaves. The Queen loved it and the new pizza was named “Pizza Margherita” in her honour.
Pizza went to America with the Italians at the end of the nineteenth century. The first pizzeria in the United States was opened in 1905 at 53 Spring Street, New York City, by Gennaro Lombardi. But the popularity of pizza really exploded when American soldiers returned from Italy after World WarⅡ and raved about(夸贊) “that great Italian dish”. Americans are now the greatest producers and consumers of pizza in the world.
【小題1】Which is the correct order of the changes of pizza?

A.Plakuntos→pizza→piceaB.Pizza→plakuntos→picea
C.Picea→plakuntos→pizzaD.Plakuntos→picea→pizza
【小題2】Why are Mexico and Peru important in the development of pizza?
A.Because pizza first became popular in these countries.
B.Because pizza was invented in these countries.
C.Because one topping was brought to Italy from these countries.
D.Because people there are the greatest consumers of pizza.
【小題3】What do the Italian flag and a Pizza Margherita have in common?
A.There is a picture of a Pizza Margherita.B.They have the same colours.
C.Both of them represent Italy.D.They are both popular in Italy.
【小題4】When did pizza become really popular in the United States?
A. After 1945.      B. In 1889.     C. In 1905.         D. By 1000AD.
【小題5】What’s the best title of the passage?
A.McDonald’s and PizzaB.Global Pizza
C.Pizza in the United StatesD.How to Make Pizza

查看答案和解析>>

科目:高中英語 來源:2012-2013學年寧夏育才中學高一下學期期中考試英語試卷(帶解析) 題型:閱讀理解

How Americans Began to Eat Tomatoes
People have strange ideas about food. For example, the tomato is a kind of very
delicious vegetable. It is one of useful plants that can be prepared in many ways. It has rich nutrition and vitamin in it. But in the 18th century, Americans never ate tomatoes. They grow them in their gardens because tomato plants are so pretty. But they thought the vegetable was poisonous (有毒的). They called tomatoes “poison apples”.
President Thomas Jefferson, however, knew that tomatoes were good to eat. He was a learned man. He had been to Paris, where he learned to love the taste of tomatoes. He grew many kinds of tomatoes in his garden. The President taught his cook a way for a cream of tomato soup. This beautiful pink soup was served at the President’s party. The guests thought the soup tasted really good. They never thought their president would serve his honored guests poison apples. Jefferson never spoke to his honored (尊貴的) guests about the fact.
【小題1】After you read the passage, which of the following do you think is true?

A.Americans never ate tomatoes after they began to plant them.
B.American didn’t eat tomatoes before the 19th century.
C.Even now Americans don’t eat tomatoes
D.In the 18th century Americans ate a lot of tomatoes.
【小題2】The passage tells us that Jefferson was a President who learned to love the taste of tomatoes.
A.while he was in Paris .
B.when he was a little boy.
C.the President ’s cook.
D.the President’s wife.
【小題3】According to the text, ________cooked the beautiful pink soup at the President ’s party?
A.the President himself.
B.A French cook
C.the President ’s cook
D.the President’s wife
【小題4】The underlined word “cook”in paragraph2 means_______
A.廚房B.廚師C.廚具D.做飯
【小題5】From the passage we know all the honored guests invited by Jefferson were______.
A.people from other countriesB.from France
C.People of his own countryD.men only

查看答案和解析>>

科目:高中英語 來源:2011-2012學年陜西省高陵縣第三中學高二下學期期末考試英語試卷(帶解析) 題型:閱讀理解

People have strange ideas about food. For example, the tomato is a kind of very delicious vegetable. It is one of useful plants that can be prepared in many ways. It has rich nutrition and vitamin in it. But in the 18th century, Americans never ate tomatoes. They grew them in their gardens because tomato plants are so pretty. But they thought the vegetable was poisonous (有毒的). They called tomatoes “poison apples.”
President Thomas Jefferson, however, knew that tomatoes were good to eat. He was a learned man. He had been to Paris, where he learned to love the taste of tomatoes. He grew many kinds of tomatoes in his garden. The President taught his cook a way for a cream of tomato soup. This beautiful pink soup was served at the President’s party. The guests thought the soup tasted really good. They never thought their president would serve his honored guests poison apples.
Jefferson never spoke to his honored (忠實的) guests about the fact.
【小題1】The passage tells us that Jefferson was a President who learned to love the taste of tomatoes       .

A.while he was in ParisB.when he was a little boy
C.because his parents told him soD.from books
【小題2】 According to the text, _______ made the beautiful pink soup served at the President’s party?
A.the President himselfB.a(chǎn) French cook
C.the President’s cookD.the President’s wife
【小題3】 From the passage we know all the honored guests invited by Jefferson were       .
A.people from other countriesB.from France
C.people of his own countryD.men only
【小題4】According to the passage, which of the following is NOT true?
A.All of the guests knew the soup that was served at the President’s party was made of tomatoes.
B.All of the guests thought the soup which was prepared by the President’s cook was nice.
C.All of the guests thought the taste of the beautiful pink soup was nice.
D.None of the guests knew that their president would serve his honored guests poison apples

查看答案和解析>>

科目:高中英語 來源:2015屆寧夏高一下學期期中考試英語試卷(解析版) 題型:閱讀理解

How Americans Began to Eat Tomatoes

People have strange ideas about food. For example, the tomato is a kind of very

delicious vegetable. It is one of useful plants that can be prepared in many ways. It has rich nutrition and vitamin in it. But in the 18th century, Americans never ate tomatoes. They grow them in their gardens because tomato plants are so pretty. But they thought the vegetable was poisonous (有毒的). They called tomatoes “poison apples”.

President Thomas Jefferson, however, knew that tomatoes were good to eat. He was a learned man. He had been to Paris, where he learned to love the taste of tomatoes. He grew many kinds of tomatoes in his garden. The President taught his cook a way for a cream of tomato soup. This beautiful pink soup was served at the President’s party. The guests thought the soup tasted really good. They never thought their president would serve his honored guests poison apples. Jefferson never spoke to his honored (尊貴的) guests about the fact.

1.After you read the passage, which of the following do you think is true?

A.Americans never ate tomatoes after they began to plant them.

B.American didn’t eat tomatoes before the 19th century.

C.Even now Americans don’t eat tomatoes

D.In the 18th century Americans ate a lot of tomatoes.

2.The passage tells us that Jefferson was a President who learned to love the taste of tomatoes.

A.while he was in Paris .

B.when he was a little boy.

C.the President ’s cook.

D.the President’s wife.

3.According to the text, ________cooked the beautiful pink soup at the President ’s party?

A.the President himself.

B.A French cook

C.the President ’s cook

D.the President’s wife

4.The underlined word “cook”in paragraph2 means_______

A.廚房             B.廚師             C.廚具             D.做飯

5.From the passage we know all the honored guests invited by Jefferson were______.

A.people from other countries               B.from France

C.People of his own country                 D.men only

 

查看答案和解析>>

同步練習冊答案