It can be seen from the passage that__...

单项选择题The idea of a fish being able to generate electricity strong enough to light lamp bulbs--or even to run a small electric motor--is almost unbelievable, but several kinds of fish are able to do this. Even more strangely, this curious power has been acquired in different ways by fish belonging to very different families. Perhaps the best known are the electric rays, or torpedoes(电鳐), of which several kinds live in warm seas. They possess on each side of the head, behind the eyes, a large organ consisting of a number of hexagonal shaped cells rather like a honeycomb. The cells are filled with a jelly-like substance, and contain a series of flat electric plates. One side, the negative side, of each plate, is supplied with very fine nerves, connected with a main nerve coming from a special part of the brain. Current passes from the upper, positive side of the organ downwards, to the negative, lower side. Generally it is necessary to touch the fish in two places, completing the circuit, in order to receive a shock. The strength of this shock depends on the size of the fish, but newly born ones only about 5 centime-tres across can be made to light the bulb of a pocket flashlight for a few moments, while a fully grown torpedo gives a shock capable of knocking a man down, and, if suitable wires are connected, will operate a small electric motor for several minutes. Another famous example is the electric eel. This fish gives an even more powerful shock. The system is different from that of the torpedo in that the electric plates run longitudinally(纵向) and are supplied with nerves from the spinal(脊骨) cord. Consequently, the current passes along the fish from head to tail. The electric organs of these fish are really altered muscles and like all muscles are apt (likely) to tire, so they are not able to produce electricity for very long. The power of producing electricity may serve these fish both for defense and attack. It can be seen from the passage that______.

A．the capacity to generate electricity is the distinctive characteristic of the fish
B．the current travels in an upward direction from the positive side to negative side in torpedo’’s electric cells
C．some fish can produce enough electricity to drive a number of electric motors
D．the torpedo’’ s electric cells have a shape with six sides

点击查看答案&解析

你可能感兴趣的试题

1.单项选择题Watch Consequences of US-Libyan Relations US Secretary of State Condoleezza Rice announced on Monday that the United Stated decided to restore full diplomatic ties with Libya and clear the nation from the list of terrorism-supporting countries. The Libyan Government welcomed the decision. This means that the 25-year-old US-Libyan confrontation comes to an end. Interpretation of this varies, the sudden announcement of the rapprochement is closely related to the issue of Iran’’s nuclear bidding. Over a long period of time,. Washington called Libya, together with Iran and others, a " rogue nation" , which allegedly supported terrorism, and was one of the seven countries that could be subject to possible US nuclear strikes. The situation altered somewhat since the outbreak of the Iraqi War in 2003. The military forces of the United States and its allies toppled the Saddam Hussein regime with the excuse that Iraq went in for weapons of mass destruction ( WMD) programmes. They did so in hopes of making the regime a public example that would pressure others to give up their alleged WMD bidding. Iran took no heed of this and went on doing what it deemed should be done. Libya, however, was co-operative, abandoning its so-called WMD programmes. For the co-operative attitude on the part of Libya, the United States gave some limited encouragement, restoring diplomatic representatives to the country in 2004. But restoration of full diplomatic relations did not occur because Libya, in the eyes of the United States, remained a "totalitarian" country, running counter to Washington’’s push for US-style freedom and democracy, even though Libya’’s co-operation in WMD issues was in the United States’’ strategic interest. The deadlock over Iran’’s nuclear bidding cornered the United States to a dilemma (进退两难的窘境): Military strikes are difficult to carry out right now and diplomatic means are yielding no significant results. It is in this context that US-Libyan ties were put on the agenda. The United States wanted to convey this message: US-Iranian ties could be restored if Iran follows Libya’’s example, despite the fact that the United States dislikes the Iranian regime. The message is naturally not only for the ear of Iran and the Democratic People’’s Republic of Korea but also for other " rogue countries" —Middle-East nations that are in the throes of transformation and some Latin American countries. The United States, for instance, decided to impose arms embargo on Venezuela almost simultaneously while it announced rapprochement with Libya. The contrast between the punishment and reward helps bring home to other countries the intention that "those who obey survive, those do not perish" in the US international strategy. To what extent this kind of "punishment and rewarding" strategy would impact the Iran and DPRK’’s nuclear bidding and those "disobedient" countries, such as Sudan and Venezuela, is worth keeping an eye on. Oil constitutes another important factor behind the rapprochement. As the second-largest oil producing country in Africa and an important nation located in the North, Libya enjoys unique geopolitical and economic value. Currently, the oil-rich Middle East is in chaos and the last thing the Bush administration wants is for the United States to become an "oil hostage" to the Middle East, where the US Government is strenuously pushing for democratic transformation. The situation is compounded by the fact that some Latin American countries are increasingly tilting to the left, threatening to become an unstable energy-resources backyard for the United States. In view of all this, opening up new energy resources-supplying bases becomes a strategic imperative for the United States. More importantly, the United States could use Libya as its military and logistical foothold in the Middle East. So in this sense, both energy-strategy and geopolitical considerations loom large behind the restoration of US-Libyan diplomatic ties. But most importantly, both security interests and oil interests are at the service of a grander strategic goal-overhauling the United States’’ African strategy. Since the end of the Cold War in the early 1990s, the US strategic focus has been shifting from Europe and the Middle East to Central Asia and the Asia-Pacific region, but Africa, a kind of "strategic vacuum area," has gone largely ignored. In the latter half of the Clinton administration, the US Government made diplomatic attempts to strengthen US -African relations, manifested by former US President Bill Clinton’’s 12-day Africa tour. But the efforts were largely watered down by a new leader in the White House and the impacts of the terror attacks on September 11 , 2001. As a result, US-African ties have made little progress over the last few years. By contrast, other major world countries have made impressive advances in Africa, taking advantage of the United States’’ non-action. Britain, France and Italy, which have traditional ties with African countries, enjoy inherent advantages in advancing relations there. China, traditionally friendly toward Africa, also enjoys a solid foundation in promoting Sino -African ties. The most pressing strategic task for the United States is, therefore, to attach great strategic importance to Africa. It is against this grand strategic backdrop that the restoration of full diplomatic ties with Libya, which still has defective human rights records by US standards, was effected. The United States’’ overseas strategy puts strategic interests first, and sidelines other factors like involving values of democracy and human rights till later on. Libya naturally has its own strategic considerations-improving relations with the United States as soon as possible so that its big-country status among African countries and in the Arab world can be restored. Where Africa is going is a question that haunts the international community. It poses a strategic question African countries themselves must answer as well. With the major world players, political as well as economic, casting their eyes on Africa, African countries face challenges and are also presented with historical opportunities. Will a chain reaction in African-US relations be triggered off by the restoration of US-Libyan diplomatic ties and by the United States’’ increasing strategic input in the continent This is a subject worth closely watching and following. Libya has never gone in for weapons of mass destruction programmes, while Iran has done it.

A．Y
B．N
C．NG

点击查看答案&解析

2.填空题If parents bring up a child with the aim of turning the child into a (36)_____, they will cause a disaster. According to several leading educational (37) _____, this is one of the biggest mistakes that (38) _____parents make. Generally, the child will be only too aware of what the parent expects, and will fail. Unrealistic parental (39) _____can cause great damage to children. However, if parents are not too (40) _____about what they expect their children to do, but are ambitious in a (41) _____way, the child may succeed in doing very well — especially if the parents are very supportive of their child. Michael Li is very lucky. He is crazy about music, and his parents help him a lot by taking him to concerts and arranging (42) _____ piano and violin lessons for him. Although Michael’’s mother knows very little about music, Michael’’s father plays the trumpet in a large (43) _____. However, he never makes Michael enter music competitions if he is unwilling. Michael’’s friend, Winston Chen, however, is not so lucky. (44)________________. They want their son to be (45)__________________. They are very unhappy when he does not win. "When I was your age, I used to win every competition I entered." Winston’’s father tells him (46)____________________.

参考答案：ambitious

3.单项选择题

A．Parents are very strict towards their children.
B．Parents work hard and have little time for their children.
C．Parents are not honest and do not practice what they advise.
D．Parents require their children to learn many new skills.

点击查看答案&解析

4.单项选择题

A．Smarter Child has his own memory bank big enough for all kinds of information.
B．A. I. Artificial Intelligence is probably the name of a film about a boy-computer.
C．Smarter Child can recognize different files and find information needed on his own.
D．We have similar product now which has the knowledge of Einstein, Nixon and Spears.

点击查看答案&解析

5.单项选择题

A．Reading.
B．Grammar.
C．Speaking.
D．Writing.

点击查看答案&解析

6.单项选择题

A．You will be sure to get everything you need.
B．You will not know how to help yourself in life.
C．You will became a man in life.
D．You needn’’t think any more in the world.

点击查看答案&解析

7.填空题If parents bring up a child with the aim of turning the child into a (36)_____, they will cause a disaster. According to several leading educational (37) _____, this is one of the biggest mistakes that (38) _____parents make. Generally, the child will be only too aware of what the parent expects, and will fail. Unrealistic parental (39) _____can cause great damage to children. However, if parents are not too (40) _____about what they expect their children to do, but are ambitious in a (41) _____way, the child may succeed in doing very well — especially if the parents are very supportive of their child. Michael Li is very lucky. He is crazy about music, and his parents help him a lot by taking him to concerts and arranging (42) _____ piano and violin lessons for him. Although Michael’’s mother knows very little about music, Michael’’s father plays the trumpet in a large (43) _____. However, he never makes Michael enter music competitions if he is unwilling. Michael’’s friend, Winston Chen, however, is not so lucky. (44)________________. They want their son to be (45)__________________. They are very unhappy when he does not win. "When I was your age, I used to win every competition I entered." Winston’’s father tells him (46)____________________.

参考答案：psychologists

8.单项选择题

A．Consistency is very important in parental teaching.
B．To forbid a thing one day and excuse it the next is the foundation for morality.
C．Parents usually spoil their children very much.
D．All parents realize that "example is better than principles".

点击查看答案&解析

9.单项选择题

A．To tell us how to spell a difficult word.
B．To tell us how the American government is run.
C．To provide as with a famous poem by Shakespeare.
D．To find where to look for information by itself.

点击查看答案&解析

10.单项选择题Watch Consequences of US-Libyan Relations US Secretary of State Condoleezza Rice announced on Monday that the United Stated decided to restore full diplomatic ties with Libya and clear the nation from the list of terrorism-supporting countries. The Libyan Government welcomed the decision. This means that the 25-year-old US-Libyan confrontation comes to an end. Interpretation of this varies, the sudden announcement of the rapprochement is closely related to the issue of Iran’’s nuclear bidding. Over a long period of time,. Washington called Libya, together with Iran and others, a " rogue nation" , which allegedly supported terrorism, and was one of the seven countries that could be subject to possible US nuclear strikes. The situation altered somewhat since the outbreak of the Iraqi War in 2003. The military forces of the United States and its allies toppled the Saddam Hussein regime with the excuse that Iraq went in for weapons of mass destruction ( WMD) programmes. They did so in hopes of making the regime a public example that would pressure others to give up their alleged WMD bidding. Iran took no heed of this and went on doing what it deemed should be done. Libya, however, was co-operative, abandoning its so-called WMD programmes. For the co-operative attitude on the part of Libya, the United States gave some limited encouragement, restoring diplomatic representatives to the country in 2004. But restoration of full diplomatic relations did not occur because Libya, in the eyes of the United States, remained a "totalitarian" country, running counter to Washington’’s push for US-style freedom and democracy, even though Libya’’s co-operation in WMD issues was in the United States’’ strategic interest. The deadlock over Iran’’s nuclear bidding cornered the United States to a dilemma (进退两难的窘境): Military strikes are difficult to carry out right now and diplomatic means are yielding no significant results. It is in this context that US-Libyan ties were put on the agenda. The United States wanted to convey this message: US-Iranian ties could be restored if Iran follows Libya’’s example, despite the fact that the United States dislikes the Iranian regime. The message is naturally not only for the ear of Iran and the Democratic People’’s Republic of Korea but also for other " rogue countries" —Middle-East nations that are in the throes of transformation and some Latin American countries. The United States, for instance, decided to impose arms embargo on Venezuela almost simultaneously while it announced rapprochement with Libya. The contrast between the punishment and reward helps bring home to other countries the intention that "those who obey survive, those do not perish" in the US international strategy. To what extent this kind of "punishment and rewarding" strategy would impact the Iran and DPRK’’s nuclear bidding and those "disobedient" countries, such as Sudan and Venezuela, is worth keeping an eye on. Oil constitutes another important factor behind the rapprochement. As the second-largest oil producing country in Africa and an important nation located in the North, Libya enjoys unique geopolitical and economic value. Currently, the oil-rich Middle East is in chaos and the last thing the Bush administration wants is for the United States to become an "oil hostage" to the Middle East, where the US Government is strenuously pushing for democratic transformation. The situation is compounded by the fact that some Latin American countries are increasingly tilting to the left, threatening to become an unstable energy-resources backyard for the United States. In view of all this, opening up new energy resources-supplying bases becomes a strategic imperative for the United States. More importantly, the United States could use Libya as its military and logistical foothold in the Middle East. So in this sense, both energy-strategy and geopolitical considerations loom large behind the restoration of US-Libyan diplomatic ties. But most importantly, both security interests and oil interests are at the service of a grander strategic goal-overhauling the United States’’ African strategy. Since the end of the Cold War in the early 1990s, the US strategic focus has been shifting from Europe and the Middle East to Central Asia and the Asia-Pacific region, but Africa, a kind of "strategic vacuum area," has gone largely ignored. In the latter half of the Clinton administration, the US Government made diplomatic attempts to strengthen US -African relations, manifested by former US President Bill Clinton’’s 12-day Africa tour. But the efforts were largely watered down by a new leader in the White House and the impacts of the terror attacks on September 11 , 2001. As a result, US-African ties have made little progress over the last few years. By contrast, other major world countries have made impressive advances in Africa, taking advantage of the United States’’ non-action. Britain, France and Italy, which have traditional ties with African countries, enjoy inherent advantages in advancing relations there. China, traditionally friendly toward Africa, also enjoys a solid foundation in promoting Sino -African ties. The most pressing strategic task for the United States is, therefore, to attach great strategic importance to Africa. It is against this grand strategic backdrop that the restoration of full diplomatic ties with Libya, which still has defective human rights records by US standards, was effected. The United States’’ overseas strategy puts strategic interests first, and sidelines other factors like involving values of democracy and human rights till later on. Libya naturally has its own strategic considerations-improving relations with the United States as soon as possible so that its big-country status among African countries and in the Arab world can be restored. Where Africa is going is a question that haunts the international community. It poses a strategic question African countries themselves must answer as well. With the major world players, political as well as economic, casting their eyes on Africa, African countries face challenges and are also presented with historical opportunities. Will a chain reaction in African-US relations be triggered off by the restoration of US-Libyan diplomatic ties and by the United States’’ increasing strategic input in the continent This is a subject worth closely watching and following. Before the announcement of the rapprochement to Libya, Libya together with Iran are the only two countries that could be subject to possible US nuclear strike.

A．Y
B．N
C．NG

点击查看答案&解析

延伸阅读

你可能感兴趣的试题