单选题From the beginning of this passage we know that.A most of the American states were prohibited to take a restB the United States of America prohibited others from restC the United States of America prohibited alcohol salesD most states in the country be

The passage warns of which of the following dangers?

The American Civil War began after the Confederate States of America seceded from the Union, in essence dividing the United States into two ______ countries.

And so it came _____ that in the United States, the most self-indulgent of nations, the tensest and most departmentalized, vacations have come to take a predominant place in domestic conversation.

The modern Internet, first established in the mid-1980s, is based on the technology developed for the ARPANET, it was created by the United States Department of Defense in the 1960s.

The passage is chiefly concerned with _____.

The author intends to tell the readers that _____.

The consequence of the three neutrality acts of the United States was（）

Practice 8　　The United States has long been known as a “melting pot”, because many of its people are descended from settlers who came from all over the world to make their homes in the new land. The first immigrants in American history came from England and the Netherlands. Attracted by reports of great economic opportunities and religious and political freedom, immigrants from many other countries flocked to the United States in increasing numbers, reaching a peak in the years 1880—1914. Between 1820 and 1980 the United States admitted almost 50 million immigrants.　　Some 1,360,000 American Indians, descendants of North America's first inhabitants, now reside in the United States. Most live in the West, but many are in the south and north central areas. Of the more than 300 separate tribes, the largest is the Navaho in the Southwest.　　Black people were first brought to America from Africa as slaves. Their descendants now make up nearly 12 percent of the population. They once lived mainly in the agricultural South but now are scattered throughout the nation.

A Nation of Immigrants Composed Mainly of the White People　　The United States of America has long been known as a nation of immigrants and a “melting pot”, because the great majority of its people are immigrants and descendants of settlers who came from all over the world to make their homes in the new land, seeking their dream in America. The　　first immigrants in American history came from England and the Netherlands. Now the descendants of European immigrants make up 80.3% of the American population of about 250 million.　　English colonization in North America in the sixteenth century repeatedly failed. It was not until 1607 that the first English permanent settlement in America was establish. The first wave of colonizing activity, which began in 1606 and lasted until 1637, planted three groups of English colonies: Virginia and Maryland on the Chesapeake, the Puritan commonwealths of New England, and the British West Indies, and also the Dutch colony of New Netherlands, which became New York. Some other European countries also established their colonies along North America’s Atlantic coastline. In 1713, the population of the twelve continental colonies was nearly 360,000, a fourfold increase. Quite a lot of them were German and Scots-Irish. Discontented Germans came to English America because the German states had no overseas possessions, and no colonies except those of the English would admit foreigners. Most Germans entered America at Philadelphia, whence they spread out fanwise into the back-country and became the most prosperous farmers in North America. The English-speaking Scots-Irish came from Ulster. They were largely descendents of the Scots who had colonized Northern Ireland when the English were first setting Virginia. After 1713 the pressure of the native Catholic Irish and the restrictive legislation of the British. Parliament forced them to emigrate in drove. As land was dear in the eastern colonies, these fighting Celts drifted to the frontier. A considerable number of southern Irish, mostly Protestants but including Catholic families came at the same time. They were mostly men of property who invested in land and remained in the older-settled regions.　　Britain gradually established its dominance over North America’s Atlantic coast. It successfully planted 13 colonies by edging out other colonial powers and by driving off the native Indians. Though the first English permanent settlement in America was established in Jamestown in1607, modem America was established in Jamestown in 1607, modem Americans choose to look back to the Pilgrim Father, a group of Puritans who came from England in 1620 for a symbol of the origin of their new country. They were followed by other Englishmen. They were generally known as the White Anglo-Saxon Protestants (WASP), who played the leading role in winning America’s independence. Their mother tongue, English, became the official language of the new nation. Today about 33% of Americans are of British origin. They control most of the national wealth and political power. The other white Americans, whose forefathers were from other European countries, are not so influential as the WASPs. All these white European immigrants and their descendants together constitute the majority of the American population.　　After the American Civil War, a large number of the “new immigrations” came to the United States of America. Even during the Civil War some 800,000 immigrants had entered the United States, and in the ten years after the ending of the war, some 3.25 million immigrants flooded into the cities and the farms of the North and the West. In the single generation from 1880 to 1910 a tidal wave of immigration spilled almost 18 million persons on American shores. Unlike the old immigrations, who were “pushed out” of West Europe by religious persecution or impoverishment, the new immigrations were “pulled to” the United States by the prospect of good jobs and happy life. Most of them were unskilled. The large influx of the new immigrations resulted in the adoption of the Immigration Quota Law by the American government.　　A lot of Chinese coolies were brought into America after the discovery of gold in California. and for the construction of the Central Pacific Railroad. The Chinese-Americans made a great contribution to the development of the American West. But, Chinese-Americans and other Asian-Americans never constitute a majority of the American population. The United States has always been a nation of immigrants composed mainly of the white people.　　Immigrants from different nations all over the world joined together to make one nation, the American. They speak almost the same kind of English with far less class or regional variety than in Great Britain. They have the same way of life, similar habits and manners. They have established a new universal national culture. With only a few exceptions, the national origins have well been mixed. In this sense, the United States of America has been known as a “melting pot”.

Which of the following would be the best title for this passage?

Questions 21 to 25 are based on the following passage. Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly. A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining. In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (区分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States. In a study published in the journal Ambio, scientists found that lead levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline. Many scientists had believed that the lead would stay in soil and snow for a longer period. The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected. Scientists say both studies demonstrate that certain parts of the ecosystem (生态系统) respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute. Lead accumulation worldwide decreased significantly after the use of unleaded gas in the US （）

Which of the following statements most clearly contradicts the information in this passage?

Stations in the United States of America are grouped by states arranged in the alphabetical order of their（）.

It can be inferred from the passage that the minimal basis for a complaint to the international Trade Commission is which of the following?

右侧50美元纸币正面主景人物头像下方的④号位置处印有缩微文字，文字内容是（）。