单选题Gas does Uaccumulate/U in the mines around here.

单选题However bad the situation is, the majority is {{U}}unwilling{{/U}} to risk change.

单选题 Kite Kite flying is the sport of sending up into the air, by means of the wind, a light frame covered with paper, plastic or doth. The frame can be one of many different shapes and is attached to a long string held in the hand or wound on a drum. Kites have a long history practical application and many different types of kite have been developed to serve various purposes. The ancient Chinese used bird-kites to carry ropes across rivers and valleys. The current folding kite which will dive excitingly is an improved type of such a kite. With its long flat body and single pair of bird like wings, it looks just like a large bird in the air. The modern version is usually made of tissue paper rather than the traditional silk. Man-lifting kites were developed in ancient times, again by the Chinese, for getting information from walled cities and army camps. In fact, as recently as World War Ⅱ, German U-boats flew kites from their towers to lift people into the air to watch the land. These kites, which are no longer in existence, were made of lightweight cloth. They were much larger and stronger than the Chinese ones. Their design, however, was simply that of the cutter kite. Smaller in size, this type of kite is still very popular as a toy for children, being easy to make with a diamond-shaped frame, no wings and brown-paper covering. Box kites are another type of kite found in toy shops today. The first box kite, named for its box-like body, was developed in the 19th century to test theories of flight and this type of cotton-covered kite greatly assisted the success of early airplanes. These kites are the ancestors of a heavier version of the box kite, called the double box kite, which consists of two main sections, placed side by side. Developed for the peacetime purpose of fishing in strong sea wind, it is the only modern kite described which has practical value. A long-lasting plastic material has to be used for this kite, which carries fishing lines.

单选题The attitude of the author towards the research project is

单选题 Transportation use a to Be Much Slower than It Is Now For many years in tile desert, camels used to be the only form of transportation. Before the (51) of modern trains, camel trains used to carry al! the goods for trading between Central Africa and Europe. Traders sometimes (52) to put together camel trains with 10,000 to 15,000 animals. Each animal often carried (53) 400 pounds and it could travel twenty miles a day. This form of transportation was so important (54) camels were called the "ship of the desert". Now modern trains travel across the desert in a very (55) time. One engine can pull as much weight as 135,000 (56) ,in addition, trains use special cars for their load. Refrigerator cars carry food; boxcars carry heavy goods; stock cars carry animals; and tank cars carry oil. (57) travel has changed, too. The earliest planes were biplanes, with two sets of wings. The top speed of this plane was 60 miles per hour. The pilots used to sit or lie on the wings in the open air. The plane (58) sometimes stopped in the middle of a trip. It used to be (59) to fly in bad weather. In snow or in rain, the wings frequently became icy. (60) the plane might go down. Mechanical improvements during the First World War changed airplanes. Monoplanes took the place of biplanes. Pilots flew inside of covered cabins. Still, even these planes were small and expensive. Only (61) people were able to travel in airplanes. Now modern jets make air travel possible for all people. (62) place in the world is more than 1 hours away by jet. Further improvements have (63) the cost of flying, and they have made air travel much safer than it used to be. A modern 707 can carry 170 people and can fly at 600 miles per hour. People (64) used to eat, sleep, or watch movies on airplanes. (65) these things are a normal part of air travel!

单选题Please Fasten Your Seatbelts Severe turbulence (湍流) can kill aircraft passengers. Now, in test flights over the Rocky Mountains, NASA (美国航空航天局) engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it. Clear-air turbulence often catches pilots by surprise. Invisible to radar, it is difficult to forecast it and can hurl (用力抛出去) passengers out of the cabin. In December 1997, one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds. However, passengers can avoid serious injury by fastening their seatbelts. "It is the only antidote (对策) for this sort of thing," says Rod Bogue, project manager at NASA"s Dryden Flight Research Center in Edwards, California. The centre"s new turbulence detector is based on lidar, laser, or radar. Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air. The technique depends on the Doppler Effect. The wavelength of the light shifts according to the speed at which the particles are approaching. In calm air, the speed equals the plane"s airspeed. But as the particles swirl (打旋) in rough air, their speed of approach increases or decreases rapidly. The rate of change in speed corresponds to the severity (激烈程度) of the turbulence. In a series of tests that began last month, a research jet flew repeatedly into disturbed air over the mountain ridges (山脉) near Pueblo, Colorado. The lidar detector spotted turbulence between 3 and 8 kilometers ahead, and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered. Bogue says that he had "a comfortable amount of time" to fasten his seatbelt. The researchers are planning to improve the lidar"s range with a more powerful beam. The system could be installed on commercial aircraft in the next few years.

单选题The most pressing problem that any country faces is how to use its scarce natural resources.A. puzzlingB. difficultC. terrifyingD. urgent

单选题The construction of the bridge goes on very well.A. instructionB. destructionC. conductionD. building

单选题Prohibition in the United States {{U}}ushered in{{/U}} an era of crime and corruption.

单选题Nobody could figure out this problem.A. make outB. think ofC. solveD. discover

单选题______ a book in his hand, he went in from the back door.A. to catchB. catchingC. caughtD. to be caught

单选题Their parents once lived under very severe conditions.

单选题The local government planned to launch a new program to help the poor.

单选题For young children, getting dressed is a {{U}}complicated{{/U}} business. A.personal B.strange C.funny D.complex

单选题The Commission has also begun looking into the {{U}}role{{/U}} of climate.

单选题I thought the rule not allowing women to compete was completely Uabsurd/U.

单选题Reading Something In English When you read to learn English composition, you 【51】 regard the language as the main thing. When you read a 【52】 in English, do you read it for the story or for the English? This is a question that is not so foolish 【53】 it may seem, 【54】 I find that many students of English 【55】 far more attention to the story than to the English. They read and enjoy and 【56】 a long time afterwards remember the story, but do not care to study the use of words and 【57】 in it. For instance, they know the plot (情节) of the story 【58】 , but do not remember a 【59】 sentence in the story and cannot tell what preposition is used before or 【60】 a certain word in the speech of a certain character(人物). Of course, it is all right to read and 【61】 and remember a story, and so long as one 【62】 to know the story only, one need not bother about the language. But the case is quite different 【63】 a student of English. I mean a student of English as distinguished (区别于)from a reader of stories or what is called the general reader. As you may have 【64】 form the above, a student of English should read very 【65】 and regard the language as the main thing.

单选题 Male-Female Expectation about Marriage The differences between men and women clarify why they have different expectations about communication in marriage. For women, talk {{U}} {{U}} 1 {{/U}} {{/U}}intimacy. Marriage is an orgy (狂欢) of {{U}} {{U}} 2 {{/U}} {{/U}}: you can tell your feelings and thoughts, and still be loved. Women's greatest fear is being pushed away. But men live in a hierarchical world, {{U}} {{U}} 3 {{/U}} {{/U}}talk maintains independence and statue. They are on {{U}} {{U}} 4 {{/U}} {{/U}}to protect themselves from being put down and pushed around. This {{U}} {{U}} 5 {{/U}} {{/U}}the paradox of the talkative man who said of his silent wife, "She's the talker." In public settings, he feels challenged to {{U}} {{U}} 6 {{/U}} {{/U}}his intelligence and display his understanding. But at home, where he has {{U}} {{U}} 7 {{/U}} {{/U}}to prove and no one to defend against, he is free to remain {{U}} {{U}} 8 {{/U}} {{/U}}. For his wife, being home means she is free from the worry that something she says might {{U}} {{U}} 9 {{/U}} {{/U}}someone, or spark disagreement, or appear to be showing off; at home she is {{U}} {{U}} 10 {{/U}} {{/U}}to talk. The communication {{U}} {{U}} 11 {{/U}} {{/U}}that endanger marriage can't be fixed by mechanical engineering. They require a new conceptual framework about the {{U}} {{U}} 12 {{/U}} {{/U}}of talk in human relationships. Many of the psychological explanations may not be {{U}} {{U}} 13 {{/U}} {{/U}}, because they tend to blame either women (for not being assertive enough) {{U}} {{U}} 14 {{/U}} {{/U}}, men (for not being in touch with their feelings). A sociolinguistic approach in {{U}} {{U}} 15 {{/U}} {{/U}}male-female conversation is seen as cross-cultural communication allows us to understand the problem and forge solutions without blaming either party.

单选题My sister has a talent for music.A. interestB. limitationC. dreamD. gift

单选题The construction of the railway is said to have been terminated.A. resumedB. endedC. suspendedD. cancelled