单选题
单选题
Not only Tom but also Alice and Mary ______ busy.
A:is B:was C:are D:has
Technically, any substance other than food that alters our bodily or mental functioning is a drug. Many people mistakenly believe the term drug refers only to some sort of medicine or an illegal chemical taken by drug addicts. They don’’t realize that familiar substances such as alcohol and tobacco are also drugs. This is why the more neutral term substance is now used by many physicians and psychologists. The phrase" substance abuse" is often used instead of" drug abuse" to make clear that substances such as alcohol and tobacco can be just as harmfully misused as heroin and cocaine. We live in a society in which the medicinal and social use of substances (drugs) is pervasive: an aspirin to quiet a headache, some wine to be sociable, coffee to get going in the morning, a cigarette for the nerves. When do these socially acceptable and apparently constructive uses of a substance become misuses First of all ,most substances taken in excess will produce negative effects such as poisoning or intense perceptual distortions. Repeated use of a substance can also lead to physical addiction or substance dependence. Dependence is marked first by an increased tolerance, with more and more of the substance required to produce the desired effect, and then by the appearance of unpleasant withdrawal symptoms when the substance is discontinued. Drugs (substances) that affect the central nervous system and alter perception, mood, and behavior are known as psychoactive substances. Psychoactive substances are commonly grouped according to whether they are stimulants, depressants, or hallucinogens. Stimulants initially speed up or activate the central nervous system, whereas depressants slow it down. Hallucinogens have their primary effect on perception, distorting and altering it in a variety of ways including producing hallucinations. These are the substances often called psychedelic ( from the Greek word meaning" mind-manifesting" ) because they seemed to radically alter one’’s state of consciousness. "Substance abuse"( Line 5, Paragraph 1 ) is preferable to" drug abuse" in that ___________.
A:substances can alter our bodily or mental functioning if illegally used B:"drug abuse" is only related to a limited number of drug takers C:alcohol and tobacco are as fatal as heroin and cocaine D:many substances other than heroin or cocaine can also be poisonous
阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。
| {{B}}? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ?
? ? ? Where Did All the Ships Go?{{/B}} ? ?The Bermuda Triangle (本角区) is one{{U}} ?(51) ?{{/U}}the greatest mysteries of the sea. In this triangular area between Florida, Puerto Rico and Bermuda in Atlantic, ships and airplanes{{U}} ?(52) ?{{/U}}to disappear more often than in{{U}} ?(53) ? {{/U}}parts of the ocean. And they do so{{U}} ?(54) ?{{/U}}leaving any sign of an accident or any dead bodies. ? ?It is{{U}} ?(55) ?{{/U}}that Christopher Columbus was the first person to record strange happenings in the area. His compass stopped working, a flame came down from the sky, and a wave 100 to 200-feet-high carried his ship about a mile away. ? ?The most famous disappearance in the Bermuda Triangle was the US Naval (海军的) Air Flight 19,{{U}} ?(56) ?{{/U}}December 5, 1945, five bomber planes carrying 14 men{{U}} ?(57) ?{{/U}}on a training mission from the Florida coast. Later that day, all communications with Flight 19 were lost. They just disappeared without a trace. ? ?The next morning, 242 planes and 19 ships took part in the largest air-sea search in history. But they found nothing. ? ?Some people blame the disappearances{{U}} ?(58) ?{{/U}}supernatural (超自然的) forces, It is suggested the{{U}} ?(59) ?{{/U}}ships and planes were either transported to other times and places, kidnapped (绑架0) by aliens (外星人){{U}} ?(60) ?{{/U}}attacked by sea creatures. ? ?There are{{U}} ?(61) ?{{/U}}natural explanations, though. The US Navy says that the Bermuda Triangle is one of two places on earth{{U}} ?(62) ?{{/U}}a magnetic compass (指南针) points towards true north{{U}} ?(63) ?{{/U}}magnetic north.{{U}} ?(64) ?{{/U}}, planes and ships can lose their way if they don’t make adjustments. ? ?The area also has changing weather and is known{{U}} ?(65) ?{{/U}}its high waves. Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident. |
A:also B:no C:barely D:hardly
阅读下面的短文，文中有15处空白，每处空白给出4个选项，请根据短文的内容从4个选项中选择1个最佳答案。
|
Where Did All the Ships Go? ? ?The Bermuda Triangle (三角区) is one {{U}}?(51) ?{{/U}} the greatest mysteries of the sea. In this triangular area between Florida, Puerto Rico and Bermuda in Atlantic, ships and airplanes {{U}}?(52) ?{{/U}} to disappear more often than in {{U}}?(53) ?{{/U}} parts of the ocean. And they do so {{U}}?(54) ?{{/U}} leaving any sign of an accident or any dead bodies. It is {{U}}?(55) ?{{/U}} that Christopher Columbus was the first person to record strange happenings in the area. His compass. stopped working, a flame came down from the sky, and a wave 100 to 200-feet-high carried his ship about a mile away. ? ?The most famous disappearance in the Bermuda Triangle was the US Naval (海军的) Air Flight 19. {{U}}?(56) ?{{/U}} December 5,1945, five bomber planes carrying 14 men {{U}}?(57) ?{{/U}} on a training mission from the Florida coast. Later that day, all communications with Flight 19 were lost. They just disappeared without a trace. ? ?The next morning, 242 planes and 19 ships took part in the largest air-sea search in history. But they found nothing. ? ?Some people blame the disappearances {{U}}?(58) ?{{/U}} supernatural (超自然的) forces, It is suggested the {{U}}?(59) ?{{/U}} ships and planes were either transposed to other times and places kidnapped (绑架) by aliens (外星人) {{U}}?(60) ?{{/U}} attacked by sea creatures. ? ?There are {{U}}?(61) ?{{/U}} natural explanations, though. The US Navy says that the Bermuda Triangle is one of two places on earth {{U}}?(62) ?{{/U}} a magnetic compass (指南针) points towards true north {{U}}?(63) ?{{/U}} magnetic north, {{U}}?(64) ?{{/U}}, planes and ships can lose their way if they don’t make adjustments. The area also has changing weather and is known {{U}}?(65) ?{{/U}} its high waves. Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident. |
A:also B:no C:barely D:hardly
阅读下面的短文，文中有15处空白，每处空白给4个选项，请根据短文的内容从4个选项中选择1个最佳答案。
| ? ?
Where Did All the Ships Go? ? ?The Bermuda Triangle (三角区) is one {{U}}?(51) ?{{/U}} the greatest mysteries of the ses. In this triangular area between Florida, ?Puerto Rico and Bermuda in Atlantic, ?ships and airplanes {{U}}?(52) ?{{/U}} to disappear more often than in {{U}}?(53) ?{{/U}} parts of the ocean. And they do so {{U}}?(54) ?{{/U}} leaving any sign of an accident or any dead bodies. It is {{U}}?(55) ?{{/U}} that Christopher Columbus was the first person to record strange happenings in the area. His compass stopped working, a flame came down from the sky, and a wave 100 to 200-feet-high carried his ship about a mile away. ? ?The most famous disappearance in the Bermuda Triangle was the US Naval (海军的) Air Flight 19．{{U}} ?(56) ?{{/U}} December 5, 1945, five bomber planes carrying 14 men {{U}}?(57) ?{{/U}} on a training mission from the Florida coast. Later that day, all communications with Flight 19 were lost. They just disappeared without a trace. ? ?The next morning, 242 planes and 19 ships took part in the largest air-sea search in history. But they found nothing. ? ?Some people blame the disappearances {{U}}?(58) ?{{/U}} supernatural (超自然的) forces. It is suggested the {{U}}?(59) ?{{/U}} ships and planes were either transposed to other times and places kidnapped (绑架) by aliens (外星人){{U}} ?(60) ?{{/U}} attacked by sea creatures. ? ?There are {{U}}?(61) ?{{/U}} natural explanations, though. The US Navy says that the Bermuda Tri angle is one of two places on earth {{U}}?(62) ?{{/U}} a magnetic compass (指南针) points towards true north {{U}}?(63) ?{{/U}} magnetic north, {{U}}?(64) ?{{/U}}, planes and ships can lose their way if they don’t make adjustments. The area also has changing weather and is known {{U}}?(65) ?{{/U}} its high waves. Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident. |
A:also B:no C:barely D:hardly
It is clear that some chemicals can damage the health of animals and humans. (1) , this is not the only problem that (2) be caused by the careless use of chemicals. Chemicals can also (3) the ecological balance of the environment. If the ecological balance is disturbed, the results can be (4) serious.The (5) of DDT illustrates the problem. DDT, a chemical which kills insects, at first seemed to be a perfect answer (6) many problems. It would control insects that caused dangerous diseases, (7) insects that caused billions of dollars of damage to crops every year. Governments permitted and even (8) the use of DDT. Farmers in many countries (9) to spray it on their crops. The (10) results were good. Damage to crops (11) down, and profits went up. However, the chemical had effects which the scientists didn’t see in (12) . First, it also killed insects which were the (13) enemies of the harmful insects and which were therefore beneficial to farmers. Second, and perhaps worse, DDT did not kill (14) harmful insect. A few insects had natural resistance to the chemical. They (15) and reproduced in large numbers. In a few years there were large numbers of insects which were not (16) by DDT, and there were (17) insects which Could act as natural (18) on these new "super-insects". Finally, it became clear that DDT was not solving the insect problem. In fact, it was making the problem worse. It (19) became necessary to find a second (20) for the effects of the first.
第（7）空应选择（）A:as well as B:as well C:but D:also
Not only Tom but also Alice and Mary ______ busy.
A:is B:was C:are D:has
Thermal energy in transition is also referred to as _____.
A:heat B:power C:horsepower D:foot-pound
