America’s greatest technological achievement, the Hoover Dam, now has a companion piece, a bridge held up by the longest arch in the Western Hemisphere（半球）. The Mike O’Callaghan-Pat Tillman Memorial Bridge, which opened this month and connects the U.S. states of Arizona and Nevada, crosses the vast chasm（峡谷）890 feet above the Colorado River that is controlled by the dam.

The striking 1,900-foot-long structure will improve traffic in the region and help protect the dam from being destroyed. It is the seventh highest bridge in the world, behind four in China, one in Papua New Guinea and one in the US state of Colorado.

“The Hoover Dam is the greatest civil engineering achievement in America’s history,” said the bridge project manager Dave Zanatell. “Our goal was not to outdo or outshine it. Our goal was to, in a respectful way, do something that would be great for our generation and that would stand besides Hoover Dam in a respectful and quality way that would become a part of Hoover’s legacy（遗产）.”

Just as the Hoover Dam was built in the heart of the Great Depression（大萧条）and was seen as an example of the nation’s can-do spirit, some hope this project can also provide some uplift.

The bridge is surprising: at 1,050 feet, its support arch holds up a roadway that lies on 300-foot-long concrete pillars（柱子）, some of the tallest in the world. It contains 16 million pounds of steel.

　　The idea of the bridge came into being in the 1960s because the top of the Hoover Dam has been a narrow two-lane road that is the fastest route from Arizona to Las Vegas and then the Pacific Northwest and Canada.

  　Access to the dam from each direction is a dangerously winding route, but massive trucks and passenger vehicles shared it for decades. During the day, when thousands of tourists travel to the dam from Las Vegas three times as many accidents as on a normal road will happen.

  　The bridge has a sidewalk on the side facing the dam. The wall on both sides is 54 inches high, so walkers can take photos there.

1.Which of the following is true of the Hoover Dam?

   A. It was completed recently.

   B. It was built during the hard times.

   C. It has the longest arch.

   D. It’s the seventh highest dam in the world.

2.What is one of the purposes of building the bridge?

   A. To protect the dam.                                            B. To save the cultures.

   C. To outdo the dam.                                                   D. To develop the tourism.

3.The underlined word “uplift” in Paragraph 4 means _____.

   A. lift of the heavy object                              B. support in money

   C. spiritual encouragement                                   D. instruction in technology

4.Which of the followings shows the right position of the bridge and dam?

5.The text is mainly about ______.

   A. the Hoover Dam                                                 

   B. American western development

   C. a tour along the Colorado River                      

   D. a recently built bridge

America’s greatest technological achievement, the Hoover Dam, now has a companion piece, a bridge held up by the longest arch in the Western Hemisphere（半球）. The Mike O’Callaghan-Pat Tillman Memorial Bridge, which opened this month and connects the U.S. states of Arizona and Nevada, crosses the vast chasm（峡谷）890 feet above the Colorado River that is controlled by the dam.

The striking 1,900-foot-long structure will improve traffic in the region and help protect the dam from being destroyed. It is the seventh highest bridge in the world, behind four in China, one in Papua New Guinea and one in the US state of Colorado.

“The Hoover Dam is the greatest civil engineering achievement in America’s history,” said the bridge project manager Dave Zanatell. “Our goal was not to outdo or outshine it. Our goal was to, in a respectful way, do something that would be great for our generation and that would stand besides Hoover Dam in a respectful and quality way that would become a part of Hoover’s legacy（遗产）.”

Just as the Hoover Dam was built in the heart of the Great Depression（大萧条）and was seen as an example of the nation’s can-do spirit, some hope this project can also provide some uplift.

The bridge is surprising: at 1,050 feet, its support arch holds up a roadway that lies on 300-foot-long concrete pillars（柱子）, some of the tallest in the world. It contains 16 million pounds of steel.

　　The idea of the bridge came into being in the 1960s because the top of the Hoover Dam has been a narrow two-lane road that is the fastest route from Arizona to Las Vegas and then the Pacific Northwest and Canada.

  　Access to the dam from each direction is a dangerously winding route, but massive trucks and passenger vehicles shared it for decades. During the day, when thousands of tourists travel to the dam from Las Vegas three times as many accidents as on a normal road will happen.

  　The bridge has a sidewalk on the side facing the dam. The wall on both sides is 54 inches high, so walkers can take photos there.

Which of the following is true of the Hoover Dam?

   A. It was completed recently.

   B. It was built during the hard times.

   C. It has the longest arch.

   D. It’s the seventh highest dam in the world.

What is one of the purposes of building the bridge?

   A. To protect the dam.                                 B. To save the cultures.

   C. To outdo the dam.                                       D. To develop the tourism.

The underlined word “uplift” in Paragraph 4 means _____.

   A. lift of the heavy object                            B. support in money

   C. spiritual encouragement                           D. instruction in technology

Which of the followings shows the right position of the bridge and dam?

The text is mainly about ______.

   A. the Hoover Dam                                    

   B. American western development

   C. a tour along the Colorado River               

   D. a recently built bridge

There are various ways in which individual economic units can interact with one another. Three basic ways may be described as the market system, the administered system, and the traditional system.

　　In a market system individual economic units are free to interact among each other in the marketplace. It is possible to buy commodities from other economic units or sell commodities to them. In a market, transactions may take place via barter or money exchange. In a barter economy, real goods such as automobiles, shoes, and pizzas are traded against each other. Obviously, finding somebody who wants to trade my old car in exchange for a sailboat may not always be an easy task. Hence, the introduction of money as a medium of exchange eases transactions considerably. In the modern market economy, goods and services are bought or sold for money.

　　An alternative to the market system is administrative control by some agency over all transactions. This agency will issue commands as to how much of each good and service should be produced, exchanged, and consumed by each economic unit. Central planning may be one way of administering such an economy. The central plan, drawn up by the government, shows the amounts of each commodity produced by the various firms and allocated to different households for consumption. This is an example of complete planning of production, consumption, and exchange for the whole economy.

　　In a traditional society, production and consumption patterns are governed by tradition; every person’s place within the economic system is fixed by parentage, religion, and custom. Transactions take place on the basis of tradition, too. People belonging to a certain group or caste（阶级） may have an obligation to care for other persons, provide them with food and shelter, care for their health, and provide for their education. Clearly, in a system where every decision is made on the basis of tradition alone, progress may be difficult to achieve. An inactive society may result.

1.What is the main purpose of the passage?

　 A. To outline contrasting types of economic systems.

　 B. To explain the science of economics.

　 C. To argue for the superiority of one economic system.

　 D. To compare barter and money-exchange markets.

2. In the second paragraph, the underlined word “real” could best be replaced by _______.

　 A. valuable         B. concrete         C. absolute            D. reliable

3.According to the passage, a barter economy can generate ______.

　 A. rapid speed of transactions               B. misunderstandings

　 C. inflation                             D. difficulties for the traders

4. According to the passage, who has the greatest degree of control in the administered system?

　 A. Individual households.                    B. Small businesses.

　 C. Major corporations.                   D. The government.

5.Which of the following is not mentioned by the author as a criterion（标准）for determining a person’s position in a traditional society?

　 A. Family background                 B. Age

　 C. Religious beliefs.                        D. Custom

There are various ways in which individual economic units can interact with one another. Three basic ways may be described as the market system, the administered system, and the traditional system.

　　In a market system individual economic units are free to interact among each other in the marketplace. It is possible to buy commodities from other economic units or sell commodities to them. In a market, transactions may take place via barter or money exchange. In a barter economy, real goods such as automobiles, shoes, and pizzas are traded against each other. Obviously, finding somebody who wants to trade my old car in exchange for a sailboat may not always be an easy task. Hence, the introduction of money as a medium of exchange eases transactions considerably. In the modern market economy, goods and services are bought or sold for money.

　　An alternative to the market system is administrative control by some agency over all transactions. This agency will issue commands as to how much of each good and service should be produced, exchanged, and consumed by each economic unit. Central planning may be one way of administering such an economy. The central plan, drawn up by the government, shows the amounts of each commodity produced by the various firms and allocated to different households for consumption. This is an example of complete planning of production, consumption, and exchange for the whole economy.

　　In a traditional society, production and consumption patterns are governed by tradition; every person’s place within the economic system is fixed by parentage, religion, and custom. Transactions take place on the basis of tradition, too. People belonging to a certain group or caste（阶级） may have an obligation to care for other persons, provide them with food and shelter, care for their health, and provide for their education. Clearly, in a system where every decision is made on the basis of tradition alone, progress may be difficult to achieve. An inactive society may result.

1.What is the main purpose of the passage?

　 A. To outline contrasting types of economic systems.

　 B. To explain the science of economics.

　 C. To argue for the superiority of one economic system.

　 D. To compare barter and money-exchange markets.

2.In the second paragraph, the underlined word “real” could best be replaced by _______.

　 A. valuable         B. concrete         C. absolute            D. reliable

3.According to the passage, a barter economy can generate ______.

 A. rapid speed of transactions             B. misunderstandings

　 C. inflation                             D. difficulties for the traders

4.According to the passage, who has the greatest degree of control in the administered system?

　 A. Individual households.                    B. Small businesses.

　 C. Major corporations.                   D. The government.

5.Which of the following is not mentioned by the author as a criterion（标准）for determining a person’s position in a traditional society?

　 A. Family background                 B. Age

　 C. Religious beliefs.                        D. Custom