From Dr. R. S. Scorer of Britain’s Imperial College of Science comes the latest theory about the cause of lightening flashes. Dr. Scorer believes the cause is hail falling through super - cooled clouds, lee particles bouncing off the falling hail acquire a positive charge and rise to the top of the cloud while the hail carries a negative charge to the bottom of the cloud.

A . A. Second Language Teaching B . B. Foreign Language Teaching C . C. Common Language Teaching D . D. Native Language Teaching

A . candle test，adding-up test，word assoviation test. B . candle test，word assoviation test，adding-up test. C . Adding-up test，candle test，word assoviation test. D . Adding-up test，word assoviation test，candle test.

A．had turned away B．were turned away C．had turned out D．were turned out

设有可导函数f,g:(a,b)→R.若<img src='https://img2.soutiyun.com/ask/2020-08-18/966610153011799.png' />则<img src='https://img2.soutiyun.com/ask/2020-08-18/966610163225383.png' />f'(x)≤g'(x),对吗？

Buses offered a more flexible service than trolleys, because they were not restricted to operating only on fixed tracks. General Motors acquired many of the privately owned streetcar companies and replaced the trolleys with buses that the company made. But bus ridership has declined from a peak of 11 billion riders per year in the late 1940s to 5 million in the 1990s. Commuter railroad service, like trolleys and buses, has also been drastically reduced in most U.S. cities. The one exception to the downward trend in public transportation in the United States is the subway, now known to transportation planners as fixed heavy rail. Cities such as Boston and Chicago have attracted new passengers through construction of new lines and modernization of existing service. Chicago has been a pioneer in the construction of heavy rail rapid transit lines in the median strip of expressways. Entirely new subway systems have been built in recent years in a number of U.S. cities, including Atlanta, Baltimore, Miami, San Francisco, and Washington, D.C. Public transportation is particularly suited to bringing a large number of people into a small area in a short period of time. Consequently, its use is increasingly confined in the United States to rush-hour commuting by workers in the central business district. A bus can accommodate thirty people in the amount of space occupied by one automobile, while a double-track rapid transit line can transport the same number of people as sixteen lanes of urban freeway. Despite modest recent successes, most public transportation systems are caught in a vicious circle, because fares do not cover operating costs. As patronage declines and expenses rise, the fares are increased, which drives away passengers and leads to service reductions and still higher fares. Public expenditures to subsidize construction and operating costs have increased, but public officials in the United States do not consider that public transportation is a vital utility deserving subsidy to the degree long assumed by European governments. In contrast, even in the relatively developed Western European countries and Japan, where automobile ownership rates are high, extensive networks of bus, tram, and subway lines have been maintained, and funds for new construction have been provided in recent years. Since the late 1960s, London has opened 27 kilometers of subways, including two new lines, plus 18 kilometers in light rail transit lines to serve the docklands area. During the same period, Paris has built 65 kilometers of new subway lines, including a new system, known as the Reseau Express Regional (R. E. R.) to serve outer suburbs. Smaller cities have shared the construction boom. In France alone, new subway lines have been built since the 1970s in Lille, Lyon, and Marseille, and hundreds of kilometers of entirely new tracks have been laid between the country's major cities to operate a high-speed train known as the TGV. Which of the following is NOT true of the public transportation systems in the developed countries？ A．Commuter railroad service, trolleys and buses have been reduced in the U. S. B．Subways have largely been maintained. C．Fares usually can not cover operating costs. D．U.S. officials think it worthwhile to subsidize public transportation.

Japan has a population of over 116,000,000. The people are thickly settled on the four main islands. Since only one sixth of the land is arable, Japan relies on imported food. To pay for the imports, Japan exports manufactured goods. Japan builds and sells cars, motorcycles, television sets, radios and cameras. Textiles and chemicals also made. In Yokohama Harbor, ships are constructed for use by other nations. The "head start" western nations had may be the reason for Japan's success today. Western countries are still using machines and technology that they developed many years ago. Japan is using newer, improved methods. For example, robots are relieving factory-workers of long, tiring jobs. Modem technology has brought modern problems. Air and water quality reached dangerous levels in some parts of Japan in the late 1960's. Since then, the Japanese government has applied strong pollution controls. The main idea of the passage is that Japan ________. A．surprises the world. B．Suffers from serious air and water pollution C．Leads in exporting goods D．Leads in technology in the world today

Why are so many firms coming to the U. S. ？ There are many reasons. One of the greatest attractions, of course, is a market of over 200 million consumers with a high average per capital income. In addition, with the devalued dollar the cost of American labor has declined significantly, relative to many foreign labor costs. Some firms seeking to avoid economic and/or political pressures at home find the U. S. a politically stable environment in which to work. Many hope to be able to continue selling to the American market even if the U. S. government restricts imports further, or if major price changes occur due to currency fluctuations (波动). Many foreigners are attracted by U.S. technology, its modem management methods, its labor saving and mass production techniques. In 1980 the largest foreign financial investor in the U. S. was from ______. A．H.K. B．U.K. C．Latin America D．South Africa

"It might seem strange that people still want to listen to instead of watching television, but this is an unusual art form. whose time has come again, "said David Amibrose, director of Beyond the Border, an international storytelling festival(节)in Wales. "Some of the tales, like those of the Inuit from Canada, are thousands years old. So our storytellers have come from distant lands to connect us with the distance of time. " he said early this month. Two Inuit women, both in their mid 60s, are among the few remaining who can do Kntadjait, or throat singing, which has few words and much sound. Their art is governed by the cold of their surroundings, forcing them to say little but listen attentively. Ambrose started the festival in 1993, after several years of working with those reviving(coming back into use or existence)storytelling in Wales. "It came out of a group of people who wanted to reconnect with traditions and as all the Welsh are storytellers, it was in good hands here." Ambrose said. 第41题：Ambrose believes that the art of storytelling. [A] will be more popular than TV [B] will be popular again [C] started in Wales [D] are in the hands of some old people

A．the multiracial constituents of the US society B．the absence of a common religion and ancestry C．the want of shared myths they possess in life D．the obstruction of achieving a general agreement

A．136． B．60． C．70． D．80．

Television pictures(A) can now be sent(B) from one side of the world to another(C) by means(D) of satellites.

A．Candle test, adding-up test, word-association test B．Candle test, word-association test, adding-up test C．Adding-up test, candle test, word-association test D．Adding-up test, word-association test, candle test

磁场沿固柱体轴线均匀分布,磁感应强度按<img src='https://img2.soutiyun.com/ask/2020-05-11/958041017968246.png' />的速率减小。圆柱体半径为R.其中a、b点离轴线的距离均为3 cm,如图8-25所示。问电子在a、b两点和O点的加速度多大？方向如何？ <img src='https://img2.soutiyun.com/ask/2020-05-11/958041026058683.png' />

是 否

A．having imagined B．being imagined C．imagine D．to be imagined

A．from verb to adjective B．from adjective to noun． C．from noun to adjective D．from noun to ver B．