文章来源：华樱外语 发布时间：2016年12月06日 点击数： 次
Paragraph 5: The political institutions of the four countries posed no significant barriers to industrialization or economic growth. The nineteenth century passed relatively peacefully for these countries, with progressive democratization taking place in all of them. They were reasonably well governed, without notable corruption or grandiose state projects, although in all of them the government gave some aid to railways, and in Sweden the state built the main lines. As small countries dependent on foreign markets, they followed a liberal trade policy in the main, though a protectionist movement developed in Sweden. In Denmark and Sweden agricultural reforms took place gradually from the late eighteenth century through the first half of the nineteenth, resulting in a new class of peasant landowners with a definite market orientation.
8. The author includes the information that “a protectionist movement developed in Sweden” in order to
¡ support the claim that the political institutions of the four countries posed no significant barriers to industrialization or economic growth
¡ identify an exception to the general trend favoring liberal trade policy
¡ explain why Sweden industrialized less quickly than the other Scandinavian countries and Netherlands
¡ provide evidence that agricultural reforms take place more quickly in countries that have a liberal trade policy than in those that do not
Paragraph2: Another flaw of the tiredness theory is that yawning does not raise alertness or physiological activity, as the theory would predict. When researchers measured the heart rate, muscle tension and skin conductance of people before, during and after yawning, they did detect some changes in skin conductance following yawning, indicating a slight increase in physiological activity. However, similar changes occurred when the subjects were asked simply to open their mouths or to breathe deeply. Yawning did nothing special to their state of physiological activity. Experiments have also cast serious doubt on the belief that yawning is triggered by a drop in blood oxygen or a rise in blood carbon dioxide. Volunteers were told to think about yawning while they breathed either normal air, pure oxygen, or an air mixture with an above-normal level of carbon dioxide. If the theory was correct, breathing air with extra carbon dioxide should have triggered yawning, while breathing pure oxygen should have suppressed yawning. In fact, neither condition made any difference to the frequency of yawning, which remained constant at about 24 yawns per hour. Another experiment demonstrated that physical exercise, which was sufficiently vigorous to double the rate of breathing, had no effect on the frequency of yawning. Again the implication is that yawning has little or nothing to do with oxygen.
1. In the paragraph 2, why does the author note that there were physiological changes when subjects opened their mouths or breathed deeply?
¡ To present an argument in support of the tiredness theory
¡ To cast doubt on the reliability of the tests that measured heart rate, muscle tension and skin conductance
¡ To argue against the hypothesis that yawning provides a special way to improve alertness or raise physiological activity
¡ To support the idea that opening the mouth or breathing deeply can affect blood oxygen levels
Paragraph 4: The empirical evidence, such as it is, suggests an altogether different function for yawning—namely, that yawning prepares us for a change in activity level. Support for this theory came from a study of yawning behavior in everyday life. Volunteers wore wrist-mounted devices that automatically recorded their physical activity for up to two weeks: the volunteers also recorded their yawns by pressing a button on the device each time they yawned. The data showed that yawning tended to occur about 15 minutes before a period of increased behavioral activity. Yawning bore no relationship to sleep patterns, however. This accords with anecdotal evidence that people often yawn in situations where they are neither tired nor bored, but are preparing for impending mental and physical activity. Such yawning is often referred to as "incongruous" because it seems out of place, at least on the tiredness view: soldiers yawning before combat, musicians yawning before performing, and athletes yawning before competing. Their yawning seems to have nothing to do with sleepiness or boredom—quite the reverse—but it does precede a change in activity level.
12. Why does the author mention “soldiers yawning before combat, musicians yawning before performing, and athletes yawning before competing”?
¡ To argue that just the expectation of physical activity can make some people feel tired
¡ To explain how the view that people yawn because they are tired accounts for yawning before stressful situations
¡ To support the view that yawning helps prepare a person for mental or physical exertion
¡ To provide anecdotal evidence that conflicts with the experience of the volunteers in the study
Paragraph 3: Most lightning takes place within a cloud when the charge separation within the cloud collapses. However, as the storm cloud develops, the ground beneath the cloud becomes positively charged and lightning can take place in the form of an electrical discharge between the negative charge of the cloud and the positively charged ground. Lightning that strikes the ground is the most likely to be destructive, so even though it represents only 20 percent of all lightning, it has received a lot of scientific attention.
1. The author remarks that “Lightning that strikes the ground is the most likely to be destructive” in order to explain why
¡ this form of lightning has been investigated so much
¡ this form of lightning is not as common as lightning within a cloud
¡ scientific understanding of this form of lightning is important
¡ the buildup of positive charge on the ground beneath a storm cloud can have serious consequences