练习七
Directions: Read the underlined sentences carefully, and then translate them into Chinese. You may check your answers after you finish them.
Passage One
As the horizons(范围) of science have expanded, two main groups of scientists have emerged. One is the pure scientist; the other, the applied scientist.
The pure or theoretical scientist does original research in order to understand the basic laws
Of nature that govern our world. The applied scientist adapts this knowledge to practical problems. Neither is more important than the other, however, for the two groups are very much related.
Sometimes, however, the applied scientist finds the problems for the theoretical scientist to work on. Lets take a particular problem of the aircraft industry: heat-resistant metals. Many of the metals and alloys which perform satisfactorily in a car cannot be used in a jet-propelled plane. New alloys must be used, because the jet engine operates at a much higher temperature than automobile engine. The turbine wheel in a turbojet must withstand temperatures as high as 1 600 degrees Fahrenheit, so aircraft designers had to the research metallurgist for the development of metals and alloys that would do the job in jet-propelled planes.
Dividing scientists into two groups pure and applied is only one broad way of classifying them, however. When scientific knowledge was very limited, there was no need for men to specialize. Today, with the great body of scientific knowledge, scientists specialize in many different fields. Within each field, there are even further subdivisions. The various sciences have become more and more interrelated until no one branch is entirely independent of the others. Many new specialties geophysics and biochemistry, for example have resulted from combining the knowledge of two or more sciences.
Passage Two
Thoughts from yesterday guide us toward tomorrow.
More than 2000 years ago, Caecilius Statius, a Roman slave who became famous as a playwright, observed, we plant trees to benefit another generation. His remark is as apt as it was when he made it and shows how thinkers of the past can still teach us something about the future.
George Bernard Show, for instance, made an even more perceptive remark. We are made wise, not by the recollection of our past, but by the responsibility for our future. This responsibility begins when we recognize that we ourselves create our future that the future is not something imposed upon us by fate or other forces beyond our control. We ourselves build the future both through what we do and what we do not do. Once we recognize our power over the future, we inevitably begin to anticipate the consequences of what we do and to do those things that will improve our future; in short, we begin to act wisely.
And our own responsibility for the future bears the promise of a better future world, because, as C. P. Snow, the novelist and philosopher, once remarked: The sense of the future is behind all good policies. Unless we have it, we can give nothing either wise or decent to the world. And our obligations must be more to the future than the past. Our greatest responsibility is to be good ancestors.
Passage Three
Criticism of research lays a significant foundation for future investigative work, but when students begin their own projects, they are likely to find that the standards of validity in field work are considerably more rigorous than the standards for most library research.
When students are faces with the concrete problem of proof by field demonstration, they usually discover that many of the important relationships they may have criticized other researcher for failing to demonstrate are very elusive indeed. They will find, if they submit an outline or questionnaire to their classmates for criticism, that other students make comments similar to some they themselves may have made in discussing previously published research. For example student researchers are likely to begin with a general question but find themselves forced to narrow its focus. They may learn that questions whose meanings seem perfectly biased to someone else. They usually find that the formulation of good research questions is a much more subtle and frustrating task than is generally believed by those who have not actually attempted it.
Passage Four
Dry regions in the south western United States have become increasingly inviting playgrounds for the growing number of recreation seekers who own vehicles such as motorcycles or powered trail bikes and indulge in hill-climbing contests or in carving new trails in the desert. But recent scientific studies show that these off-road vehicles can cause damage to desert landscapes that has long-range effects on the areas water-conserving characteristics and on the entire ecology , both plant and animal. Research by scientists in the western Mojave Desert in California revealed that the compaction of the sandy dry soil resulting from the passage of just one motorcycle markedly reduced the infiltration ability of the soil and created a stream of rain runoff water that eroded the hillside surface. In addition, the researchers discovered that the soil compaction caused by the off-road vehicles often killed native plant species and resulted in the invasion of different plant species within a few years. The native perennial species required many more years before they showed signs of returning. The scientists calculated that roughly a century would be required for the infiltration capacity of the Mojave soil to be restored after being compacted by vehicles.
国内英语资讯:Xi stresses military-civilian integration in new era
国内英语资讯:Light show at major Budapest hotel for EU-China 2018 Tourism Year
国内英语资讯:China calls for U.S. restraint on trade protectionism
文在寅称慰安妇问题没完,日本提出抗议
国际英语资讯:Spotlight: waves surging, fights cancelled, power out as windstorm hits U.S. East Coast
体坛英语资讯:Copa Libertadores to drop home and away final format
体坛英语资讯:Ukraines Svitolina defends Dubai Open womens singles title
创纪录!新漫威神作《黑豹》,票房首超《神奇女侠》!
“抢红包”,用英语怎么说?
When Opportunity Comes 当机会来临
体坛英语资讯:Ronaldinho: Neymar to bring Brazil World Cup joy
2018年全国两会热点前瞻
涉嫌向总统大儿子寄白色粉末,一名男子被逮捕
国内英语资讯:Chinese, U.S. senior officials highlight cooperation to settle trade disputes
Does China Has Highways? 中国有高速公路吗?
国际英语资讯:Feature: Oldest house in Athens gives glimpse of life some 500 years ago
国内英语资讯:CPC Party School studies spirit of 19th CPC National Congress
西方银行争抢“一带一路”蛋糕
A lack of women in science 科学领域缺少女性工作者
国际英语资讯:Israeli police question Netanyahu, wife separately in corruption case
体坛英语资讯:Federer becomes most decorated Laureus winner with double victories in 2018
体坛英语资讯:Monchengladbach win, Hoffenheim held in German Bundesliga
国际英语资讯:Syrian army airdrops leaflets over Eastern Ghouta to urge civilians to leave, rebels to surr
体坛英语资讯:BBC on form as Real Madrid beat Alaves 4-0
这组漫画高能了!中国姑娘让你秒懂中西方文化差异(组图)
体坛英语资讯:Bayerns Coman sidelined several weeks
体坛英语资讯:Schwartzman, Verdasco reach Rio Open final
体坛英语资讯:Messi and Suarez on the mark as Barca cruise past Girona
亚洲共享单车折戟欧洲市场
《权游》所有演员都是假发?那黄老板呢...
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |