2017 年 12 月大学英语四级考试真题（第 2 套）

Technological changes brought dramatic new options to Americans living in the 1990s. During this decade new forms of entertainment, commerce, research, and communication became commonplace in the U. S. The driving force behind much of this change was a(n) __26__ popularly known as the Internet.

The Internet was developed during the 1970s by the Department of Defense. In the case of an attack, military advisers suggested the __27__ of being able to operate one computer from another terminal. In the early days, the Internet was used mainly by scientists to communicate with other scientists. The Internet __28__ under government control until 1984.

One early problem faced by Internet users was speed. Phone lines could only transmit information at a __29__ rate. The development of fiber-optic(光纤) cables allowed for billions of bits of information to be received every minute. Companies like Intel developed faster microprocessors, so personal computers could process the __30__ signals at a more rapid rate.

In the early 1990s, the World Wide Web was developed, in large part, for __31__ purposes. Corporations created home pages where they could place text and graphics to sell products. Soon airline tickets, hotel __32__, and even cars and homes could be purchased online. Universities __33__ research data on the Internet, so students could find __34__ information without leaving their dormitories. Companies soon discovered that work could be done at home and __35__ online, so a whole new class of telecommuters began to earn a living from home offices unshaven and wearing pajamas (睡衣).

Nobody really knows how big Lagos is. What's indisputable is that it's growing very quick between now and 2050, the urban population of Africa could triple. Yet cities in sub-Saharan Africa are not getting richer the way cities in the rest of the world have. Most urban Africans live in slums (贫民窟); migrants are often not much better off than they were in the countryside. Why?

The immediate problem is poverty. Most of Africa is urbanizing at a lower level of income than other regions of the world did. That means there's little money around for investment that would make cities liveable and more productive. Without upgrades and new capacity, bridges, roads and power systems are unable to cope with expanding populations. With the exception of South Africa, the only light rail metro system in sub-Saharan Africa is in Addis Ababa, Ethiopia. Traffic jam leads to expense and unpredictability, things that keep investors away.

In other parts of the world, increasing agricultural productivity and industrialization went together. More productive farmers meant there was a surplus that could feed cities; in turn, that created a pool of labour for factories. But African cities are different. They are too often built around consuming natural resources. Government is concentrated in capitals, so is the money. Most urban Africans work for a small minority of the rich, who tend to be involved in either cronyish (有裙带关系的) businesses or politics. Since African agriculture is still broadly unproductive, food is imported, consuming a portion of revenue.

So what can be done? Though African countries are poor, not all African cities are. In Lagos, foreign oil workers can pay as much as $ 65,000 per year in rent for a modest apartment in a safe part of town. If that income were better taxed, it might provide the revenue for better infrastructure. If city leaders were more accountable to their residents, they might favour projects designed to help them more. Yet even as new roads are built, new people arrive. When a city's population grows by 5% a year, it is difficult to keep up.

For the past several decades, it seems there's been a general consensus on how to get ahead in America: Get a college education, find a reliable job, and buy your own home. But do Americans still believe in that path, and if they do, is it attainable?

The most recent National Journal poll asked respondents about the American dream, what it takes to achieve their goals, and whether or not they felt a significant amount of control over their ability to be successful. Overwhelmingly, the results show that today, the idea of the American dream—and what it takes to achieve it— looks quite different than it did in the late 20th century.

By and large, people felt that their actions and hard work—not outside forces— were the deciding factor in how their lives turned out. But respondents had decidedly mixed feelings about what actions make for a better life in current economy. In the last seven years, Americans have grown more pessimistic about the power of education to lead to success. Even though they see going to college as a fairly achievable goal, a majority—52 percent—think that young people do not need a four- year college education in order to be successful.

Miguel Maeda, 42, who has a master's degree and works in public health, was the first in his family to go to college, which has allowed him to achieve a sense of financial stability his parents and grandparents never did.

While some, like Maeda, emphasized the value of the degree rather than the education itself, others still see college as a way to gain new perspectives and life experiences.

Sixty-year-old Will Fendley, who had a successful career in the military and never earned a college degree, thinks "personal drive" is far more important than just going to college. To Fendley, a sense of drive and purpose, as well as an effective high-school education, and basic life skills, like balancing a checkbook, are the necessary ingredients for a successful life in America.