Ants have a reputation for strength,organization and teamwork.But researchers have now discovered that a key secret to the success of ants is their ability to identify the importance of age in the wor 题目和参考答案——青夏教育精英家教网—

题目内容

Ants have a reputation for strength,organization and teamwork.But researchers have now discovered that a key secret to the success of ants is their ability to identify the importance of age in the work place.

A study of Gentral American leaf-cutter ants has shown that the younger and stronger members are give the toughest job of cutting therough the leaves they harvest.Their sharp youn teeth do this job effectively,but as they get older their teeth become relatively worn and blunt.

But rather than being retired or abandoned by the group,the ageing ants are given a new role more suyted to their physical abilities.They become carriers and teansport the leaves back to the kingdom where they are harvested for food.

The findings by researchers from the University of Oregon and the Oregong State University support previous research showin the survival of a leaf-cutter kingdom depends on the efficiency(效率）of is workers.

“Cuting leaves is hard work,”said Dr.Robert Schofield,who led the research team.“Much of the cutting is done with a V-shaped blade(刀片）between teeth on their jaws.This blade starts out as sharp as the sharpest razor blade that humans have developed.”But over rime the teeth become blunter and the cutting job slows down.The team estimated that,because of this age-related wear,a colony(蚁群)spent twice the energy cutting leaves than it would if all the ants had sharp blades.Its findings support the idea that wear and break can be significant problems for insects as well as largre animals.

Like humans,leaf-cuttre ant recognize that older members of the group can still make a worhwhile contribution to society.“This study shows an advantage of social living that we are familiar with,”said Dr.Schofield.

1.The younger and stronger ants do the toughest job because .

A．they can teansport the leaves effectively

B．they have a sharp blade to cut leaves

C．other members are busy with other work

D．they can finish the job in a better organized way

2.The undrelined word“blunt”in the second paragraph can be replaced by .

A．quite loose	B．less sharp
C．quite fragile	D．more dirty

3.What happens to the ants when they become old?

A．They no longer hve work to do.

B．They keep doing the same work.

C．They have to leave and live on themselves.

D．They are given a new worthwhile job.

4.It can be learned from the passage that .

A．Dr.Schofield is the first to research leaf-cuttre ants

B．older ants are more powerful in carrying leaves

C．large animals can also suffer from some kind of wear

D．leaf-cutter ants are the most lever ants in the world

5.What can be the best title for the passage?

A．The key secret to the success of ants

B．The developed structure of ant colony

C．The most challenging job for leaf-cutter ants

D．No V-shaped blade,no success of ants

【答案】

1.B

2.B

3.D

4.C

5.A

【解析】略

练习册系列答案

相关题目

Researchers believe that the insect(昆虫) is better at managing congestion (拥挤) than humans. Ants are the most many type of animal on earth with brains that contain about 250,000 cells ---- the largest among insects.

Now an intelligence expert Dr. Dirk Helbing says understanding more about ants could help solve one of the headaches of modern life -- road congestion.

His team set up an "ant motorway" with two routes of different widths from the nest to some sugar syrup (糖浆). Soon the narrower（更窄的） route soon became crowded（拥挤的）. But when an ant returning along the crowded route to the nest met with another ant just starting out, the returning ant pushed the newcomer onto the other path. However, if the returning ant had enjoyed a trouble-free journey, it did not send the newcomer in a different direction.

The result was that just before one route became clogged , the ants had turned to another route and traffic jams never formed.

The researchers also created a computer model of more complex ant networks with routes of different lengths. The team found that even though ants being sent in another direction sometimes took a longer route, they still got to the food quickly and efficiently.

Dr. Helbing, of the Dresden University of Technology in Germany, said that while you cannot allow cars to meet with traffic coming in the opposite（相反的）direction as a form of traffic control, you could do the next best thing and allow them to communicate.

His plan is to force cars traveling in one direction to tell oncoming traffic what the conditions they are about to meet with-- so they can avoid that situation if necessary.

The first paragraph suggests that _______.

A. ants have a special way to manage congestion

B. ants are clever and good at dealing with the traffic jams because of developed brain

C. insects are similar to animals in dealing with the traffic jams because of developed brain

D. insects have more advantages than humans

The underlined word "clogged" can be replaced by _______ in the following four words.

A. cleaned B. narrowed C. crowded D. shortened

If an ant returns along crowded route to the nest, how does the ant solve the traffic problem?

A. The ant will change the direction of its own.

B. The ant stopped the newcomer from moving ahead and forced the newcomer to wait there patiently.

C. The ant can't direct the newcomer.

D. The ant will push the newcomer to the other route, so traffic jams won't form.

What's the advice that Dr. Helbing gives us?

A. The cars cannot be allowed to communicate with traffic coming in the opposite direction.

B. The cars can communicate with traffic in the same direction.

C. The cars that travel in one direction can tell oncoming traffic about the traffic conditions.

D. We should build more routes of different lengths and widths.

E
When an ant dies, other ants take it out of the nest, often within an hour after its death. This behavior interests scientists and they wonder how ants know for sure—and so soon—that another ant is dead.
One scientist recently came up with a way to explain this ant behaviour. Dong-Hwan Choe is a biologist, a scientist who studies animals and plants. He found that ants have a chemical on the outside of their bodies that signals to other ants, “I'm dead—take me away” when it is dead.
But there's a question to answer: As we know, if an ant is dead, it stops moving. But when an ant is sleeping or knocked unconscious, it is also not moving. However, other ants don't move the living ant out of the nest. How do they know this ant is not dead? Choe found that ants have another chemical on their bodies, which tells nearby ants something like, “Wait—I'm not dead yet”when it is not dead. Choe suspects that when an ant dies, the chemical that says, “Wait I'm not dead yet”quickly goes away. When other ants detect the“dead”chemical without the“not dead yet”chemical, they move away the body.
To test his theory , Choe and his team put different chemicals on ants. When the scientists used the “I'm dead” chemical, other ants quickly moved the treated ant away. When the scientists used the“Wait—I'm not dead yet”chemical, other ants left the treated ant alone. Choe believes this behavior shows that the“not dead yet”chemical overrides the“dead” chemical when picked up by other ants. And that when an ant dies, the “not dead yet” chemical fades away. Other nearby ants then detect the remaining“dead”chemical and remove the body from the nest.
Understanding this behavior can help scientists figure out how to stop ants from invading new places and causing problems.
57. What is the function of the first paragraph?
A. Leading the following paragraphs.
B. Showing the main idea of the passage.
C. Introducing the background of the passage.
D. Giving a summary of the passage.
58. Which of the following has the closest meaning to the underlined word “overrides” in the fourth paragraph?
A.is weaker than B. is stronger than C. is better than D. is worse than
59. What can we learn from the passage?
A. Living ants can also be taken away when they are not moving.
B. When an ant dies, it can tell others using a certain chemical.
C. A living ant can pretend to be dead using a special chemical.
D. Ants often use chemicals to communicate with each other.
60. Which of the following descriptions about Dong-Hwan Choe is right?
A. Choe did this study in order to stop ants from invading new places.
B.Choe is a biologist who is only interested in animals, especially in ants.
C. Choe first came up with an idea to explain this ant behavior，and then did some tests to prove his theory.
D. Choe did the research on this ant behavior on his own

Every day Yang Hongwei takes the bus home from work, staring silently at the European-style villas(别墅), luxury cars and twinkling lights from the shopping center that he sees through the window.
Yang works for a software company in Zhongguancun. He dreams of such a life, away from poverty, and that hope has kept him in Beijing for three years since he graduated from university.
Soon Yang squeezes his way off the bus to the reality of his life: his home—a 10-square-metre room that costs 550 yuan(81 US dollars) or about one-fifth of his salary in rent every month. It’s very cold inside the house as it has no central heating system. He has to stand the long and cold winter. Determined to achieve his dream, Yang says he has changed jobs “numerous” times in the past three years and is considering quitting his present job.
Yang’s frustration over his life as a migrant(移民) is shared by many other graduates that have moved into big cities. Together they have come to be called the “ant tribe”, a term created by Chinese sociologists to describe the struggles of young migrants, who, armed with their diplomas, flood to big cities in hopes of a better life only to put up with low-paying jobs and poor living conditions. They share every similarity with ants. They live in colonies in crowded areas. They’re intelligent and hardworking, yet unknown and underpaid. The term, sociologists have said, also reflects their helplessness in a world governed by the law of the concrete jungle—only the strongest survive.
A survey in Ant TribeⅡ found nearly 30 percent of the “ants” are graduates of famous key universities—almost three times the percentage of 2009. Most have degrees in popular majors, such as medicine, engineering, economics and management. In addition, 7.2 percent of the “ants” have at least a master’s degree compared to 1.6 percent in 2009. Most said the economic recovery did not really improve their financial situations, and 66 percent said their incomes fell short of their expectations, the survey also found.
For two years, Lian Si, a post-doctoral fellow at the Center for Chinese and Global Affairs of Peking University, who has studied the phenomenon, led a team of more than 100 graduate students to follow the groups in university towns like Beijing, Shanghai, Guangzhou, Wuhan and Xi’an. Lian evaluates the total population of the “ant community” in major cities at one million across China, with about 100,000 found in Beijing alone. Lian predicts that an increasingly challenging job market will see the ant tribe growing further in number. Another 6.3 million graduates are expected to join migrant workers and other job hunters in what promises to be a fierce labour competition.
The ant tribe’s embarrassing living situations have become a serious social issue, and the government should develop “second-and-third-tier cities” to attract more graduates from big cities. However, “ants” expect more study and training opportunities in big cities, which keeps them in positive mindsets despite their situations. As in the case of Yang, he is optimistic about getting a new job soon, having received eight interview offers in a week after sending out his resume. The prospect of landing a higher-paying job keeps him hopeful of moving out of the slum district(贫民区) soon. The sooner the better.
【小题1】. Yang has worked in Beijing since graduation from university ______.

A．to live in a beautiful villa of European style

B．to have more opportunities to be promoted

C．to struggle for a better-off life in a big city

D．to enjoy a busy life in a software company

【小题2】. Which of the following best describes “ant tribe”?

A．It refers to the group of low-income graduates living in embarrassing conditions.

B．It refers to the people who work hard like ants but are paid little.

C．It refers to the sociologists and scholars researching into some social phenomena.

D．It refers to some well-educated people who can’t survive in society.

【小题3】. What does the writer think of the phenomenon of “ant tribe”?

A．“Ant tribe” has become too serious a social problem to solve.

B．It is the government’s duty to solve the problem of “ant tribe”.

C．Both the government and the graduates have the responsibility.

D．The existence of “ant tribe” has little influence on job markets.

【小题4】. The passage is mainly about ______.

A．a new urban life style—“ant tribe”	B．a recent survey about the “ant tribe”
C．the “ant tribe’s” living conditions	D．the “ant tribe’s” dream and reality

When an ant dies, other ants take it out of the nest, often within an hour after its death. This behavior interests scientists and they wonder how ants know for sure—and so soon—that another ant is dead.

One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist, a scientist who studies animals and plants. He found that ants have a chemical on the outside of their bodies that signals to other ants, “I'm dead—take me away” when it is dead.

But there's a question to answer: As we know, if an ant is dead, it stops moving. But when an ant is sleeping or knocked unconscious, it is also not moving. However, other ants don't move the living ant out of the nest. How do they know this ant is not dead? Choe found that ants have another chemical on their bodies, which tells nearby ants something like, “Wait—I'm not dead yet” when it is not dead. Choe suspects that when an ant dies, the chemical that says, “Wait— I'm not dead yet” quickly goes away. When other ants detect the “dead” chemical without the “not dead yet” chemical, they move away the body.

To test his theory, Choe and his team put different chemicals on ants. When the scientists used the “I'm dead” chemical, other ants quickly moved the treated ant away. When the scientists used the “Wait—I'm not dead yet” chemical, other ants left the treated ant alone. Choe believes this behavior shows that the “not dead yet” chemical is stronger than the “dead” chemical when picked up by other ants. And that when an ant dies, the “not dead yet” chemical fades away. Other nearby ants then detect the remaining “dead” chemical and remove the body from the nest.

Understanding this behavior can help scientists figure out how to stop ants from invading new places and causing problems.

1.What is the function of the first paragraph?

A. Leading the following paragraphs.

B. Showing the main idea of the passage.

C. Introducing the background of the passage.

D. Giving a summary of the passage.

2.What can we learn from the passage?

A. Living ants can also be taken away when they are not moving.

B. When an ant dies, it can tell others using a certain chemical.

C. A living ant can pretend to be dead using a special chemical.

D. Ants often use chemicals to communicate with each other.

3.Which of the following descriptions about Dong-Hwan Choe is right?

A. Choe did this study in order to stop ants from invading new places.

B. Choe is a biologist who is only interested in animals, especially in ants.

C. Choe first came up with an idea to explain this ant behavior, and then did some tests to prove his theory.

D. Choe did the research on this ant behavior on his own.

4.What is mainly discussed in the passage?

A. experiments about how ants manage to keep their nests clean.

B. experiments about why ants have special chemicals on their bodies.

C. experiments about why ants can have this removal behavior

D. experiments about how to decide whether an ant is dead or not.

One scientist recently came up with a way to explain this ant behaviour. Dong-Hwan Choe is a biologist, a scientist who studies animals and plants. He found that ants have a chemical on the outside of their bodies that signals to other ants, “I'm dead—take me away” when it is dead.

But there's a question to answer: As we know, if an ant is dead, it stops moving. But when an ant is sleeping or knocked unconscious, it is also not moving. However, other ants don't move the living ant out of the nest. How do they know this ant is not dead? Choe found that ants have another chemical on their bodies, which tells nearby ants something like, “Wait—I'm not dead yet” when it is not dead. Choe suspects that when an ant dies, the chemical that says, “Wait I'm not dead yet” quickly goes away. When other ants detect the “dead” chemical without the “not dead yet” chemical, they move away the body.

To test his theory , Choe and his team put different chemicals on ants. When the scientists used the “I'm dead” chemical, other ants quickly moved the treated ant away. When the scientists used the “Wait—I'm not dead yet” chemical, other ants left the treated ant alone. Choe believes this behavior shows that the “not dead yet” chemical overrides the “dead” chemical when picked up by other ants. And that when an ant dies, the “not dead yet” chemical fades away. Other nearby ants then detect the remaining “dead” chemical and remove the body from the nest.

Understanding this behavior can help scientists figure out how to stop ants from invading new places and causing problems.

1.What is the function of the first paragraph?

A. Leading the following paragraphs.

B. Showing the main idea of the passage.

C. Introducing the background of the passage.

D. Giving a summary of the passage.

2.Which of the following has the closest meaning to the underlined word “overrides” in the fourth paragraph?

A. is weaker than B. is stronger than C. is better than D. is worse than

3. What can we learn from the passage?

A. Living ants can also be taken away when they are not moving.

B. When an ant dies, it can tell others using a certain chemical.

C. A living ant can pretend to be dead using a special chemical.

D. Ants often use chemicals to communicate with each other.

4.Which of the following descriptions about Dong-Hwan Choe is right?

A. Choe did this study in order to stop ants from invading new places.

B. Choe is a biologist who is only interested in animals, especially in ants.

C. Choe first came up with an idea to explain this ant behavior，and then did some tests to prove his theory.

D. Choe did the research on this ant behavior on his own

试题分类