2020考研英語閱讀理解精讀100篇：Unit 47

Unit 47

Usually alternating current（AC）transmission suffers lower losses than direct current（DC）, and thus, AC became the industry standard. Some people, however, question that standard because over long distances high-voltage DC lines suffer lower losses than AC. Not only does that make them better in their own right, but employing them would allow electricity grids to be restructured in ways that would make wind power more attractive. That would reduce the need for new conventional（and polluting） power stations.

Wind power has some problems. You don’t always get it where you want it and you don’t always get it when you want it. The question of where the wind is blowing would no longer matter because it is almost always blowing somewhere. If it were windy in Spain but not in Ireland, current would flow in one direction. Dealing with when the wind blows is a subtler issue. For instance, an important part of Dr Schmid’s continental grid is the branch to Norway. It is not that Norway is a huge consumer. Rather, the country is well supplied with hydroelectric plants. These are one of the few ways that energy from transient sources like the wind can be stored in grid-filling quantities. The power is used to pump water up into the reservoirs that feed the hydroelectric turbines. That way it is on tap when needed. The capacity of Norway’s reservoirs is so large, according to Dr Schmid, that should the wind drop all over Europe—which does happen on rare occasions—the hydro plants could spring into action and fill in the gap for up to four weeks.

Put like this, a Europe-wide grid seems an obvious idea. That it has not yet been built is because AC power lines would lose too much power over such large distances. Hence the renewed interest in DC. Dr Schmid calculates that a DC grid of the sort he envisages would allow wind to supply at least 30% of the power needed in Europe. Moreover, it could do so reliably—and that means wind power could be used for what is known in the jargon as base-load power supply.

Though wind power has its opponents, too, its environmental virtues might be enough to swing things in its favour if it were also reliable. Indeed, a group of Norwegian companies have already started building high-voltage DC lines between Scandinavia, the Netherlands and Germany, though these are intended as much to sell the country’s power as to accumulate other people’s. And Airtricity—an Irish wind-power company—plans even more of them. It proposes what it calls a Supergrid. This would link offshore wind farms in the Atlantic Ocean and the Irish, North and Baltic seas with customers throughout northern Europe.

注（1）：本文選自Economist；

注（2）：本文習題命題模仿對象為2004年真題Text 3。

1. By saying “make them better in their own right” （Lines 3~4, Paragraph 1）, the author means to _______.

A) realize the right of DC

B) make DC suffer lower losses

C) make DC more useful than AC

D) make better use of DC to transfer power

2. By saying “Dealing with when the wind blows is a subtler issue” （Line 4, Paragraph 2）, the author actually implies that _______.

A) it is more difficult to predict the time when the wind blows

B) it is more intricate to deal with the wind since it is always transient

C) it is more complex to control the wind in the temporal sense

D) it is more complicated to utilize the wind power

3. How will consumers think of a DC electricity grid?

A) Not feasible yet.

B) Quite economical.

C) Somewhat troublesome.

D) Too bold.

4. Why is Dr Schmid’s continental grid located in Norway?

A) To make use of the country’s capacity of reservoirs so as to store temporary power.

B) To make use of the country’s rich wind power so as to meet consumers’ demand.

C) To make better use of the country’s rich hydroelectric power to supply other European countries.

D) It is simply Dr Schmid’s personal preference of that country.

5. Which of the following is TRUE according to the passage?

A) Wind power has won universal support.

B) Companies hesitate to invest in wind power.

C) The prospect of wind power so far seems very positive.

D) Wind farms on oceans can supply power demand of the whole Europe in the future.

篇章剖析

本文是一篇科技說明文，主要說明了風能發(fā)電的優(yōu)勢和可行性。第一段通過比較說明直流電和交流電來引出風能發(fā)電的話題；第二段分析了風能發(fā)電存在的一些限制及其解決辦法；第三段和第四段則說明了在歐洲建設新型電網(wǎng)的前景。

詞匯注釋

alternating current 交流電

direct current 直流電

voltage /?v??lt?d?/ n. 電壓，伏特數(shù)

electricity grid 電網(wǎng)

subtle /?s?tl/ adj. 微妙的；精細的

turbine /?t??b?n/ n. 渦輪

envisage /?n?v?z?d?/ v. 正視，設想

jargon /?d?ɑ?g?n/ n. 行話

Scandinavia /?sk?nd??ne?vj?/ n. 斯堪的納維亞（半島）

offshore /??f???/ adj. 向海面吹的，離岸的

難句突破

Not only does that make them better in their own right, but employing them would allow electricity grids to be restructured in ways that would make wind power more attractive.

主體句式：Not only does that make them better, but employing them would allow electricity grids to...

結構分析：這個句子是一個相對比較復雜的not only, but （also）結構。前半句中的not only后面跟的句子按照語法規(guī)則需要倒裝，后半句but also結構中省略了also這個詞，這在語法上也是允許的，且后半句的主句是一個現(xiàn)在分詞結構，后面的in ways之后跟的是一個定語從句。

句子譯文：這不僅能有利于電流的傳送，而且通過使用高壓直流電纜，人們可以對電網(wǎng)進行改造，從而更加有利于風能發(fā)電。

題目分析

1. D 語義題。根據(jù)文章第一段，由于在遠距離傳輸方面高壓直流電纜損失的電量比交流電纜少，因此通過這個方法能夠更加充分地利用直流電來傳輸電能，因此答案為D。

2. C 語義題。文章第二段指出利用風能存在很多問題，包括風向的時間和地點。而哪里有風的問題相對比較容易解決，但是風在什么時候吹則是一個更加微妙的問題，也就是說，在時間意義上控制風能是比較困難和復雜的，因此C選項符合題意。

3. B 細節(jié)題。文章第三段指出，建設直流電電網(wǎng)可以節(jié)約在傳輸過程中浪費的電能，因此對于消費者來說這一方案是較為經濟和節(jié)約的，也是可行的，因此正確答案為B。需要指出的是讀者應區(qū)分economic和economical兩個詞語的區(qū)別，economic的意思是“經濟（上）的，經濟學的”，是宏觀意義上的；而economical的意思是“節(jié)約的，儉省的”，是微觀意義上的。

4. A 細節(jié)題。文章第二段后半部分描述了史密德博士設計的大陸電網(wǎng)，其中指出選擇挪威的原因不是因為這個國家缺乏足夠的電能，而是這里有足夠多的水庫可以用來儲存由風能轉化而成的電能。

5. C 細節(jié)題。各個題目的細節(jié)均可以在文章最后一段中找到對應的信息。其中提到了歐洲多家能源公司已經在計劃建設傳輸風能的直流電纜，充分說明了風能利用的前景非常好。

參考譯文

一般來說，交流電傳輸比直流電傳輸損失的電量要少，因此，交流電成為了工業(yè)上的標準。但是一些人卻在質疑這個標準，因為從遠距離傳輸來看，高壓直流電纜損失的電量比交流電纜少。這不僅能有利于電流的傳送，而且通過使用高壓直流電纜，人們可以對電網(wǎng)進行改造，從而更加有利于風能發(fā)電。如此一來，對于新建更多傳統(tǒng)（也是污染的）發(fā)電站的需求就會減少。

風能發(fā)電存在一些問題。風能不是隨處都在，也非隨時可得。但是現(xiàn)在哪里有風的問題已經得到解決，因為總有地方在刮風。如果現(xiàn)在西班牙多風而愛爾蘭卻無風，那么電流就會朝一個方向傳送。但是，風在什么時候吹則是一個更微妙的問題。比如說，史密德博士設計的大陸電網(wǎng)的重要一部分就位于挪威。但這并不是因為挪威消費很多的電能，而是這個國家到處都是水電站。利用水電站是可以把如風能等稍縱即逝的能源大量儲存起來的方式之一。通過使用這些風能，人們可以把水往上抽到水庫中推動水電渦輪。水電站以這個方式就可以隨時把水抽上來。史密德博士認為挪威水庫容量如此之大，以至于如果歐洲所有的地方都不刮風了——這種現(xiàn)象確實偶爾會發(fā)生——挪威的水電站仍然可以繼續(xù)運轉并供應整個歐洲的用電量達四周之久。

如果情況真是這樣的話，那么建設一個跨歐洲的電網(wǎng)是勢在必行的了。此前沒有進行該項目建設是因為交流電纜在進行如此遠距離傳輸?shù)臅r候會損失大量的電能。而現(xiàn)在人們開始思考用直流電纜來實現(xiàn)這一設想。史密德博士估計，他設想的這種直流電纜能夠使風能滿足全歐洲至少30%的用電需求。此外，這樣做也非常可靠——從術語上說，這意味著風能可以被稱為是基本負荷型電能供應。

盡管對于風力發(fā)電也有反對者，但是如果風能可靠的話，那么其清潔環(huán)保的特點足以贏得廣泛的支持。實際上，一些挪威的公司已經開始在斯堪的納維亞、荷蘭和德國之間建設高壓直流電纜，盡管他們的目的在于銷售本國的能源并積累他人的能源。此外，一家愛爾蘭風能公司Airtricity則計劃比挪威的公司們做的更多。該公司提出了一個所謂的超級電網(wǎng)的概念，該電網(wǎng)能夠將大西洋、愛爾蘭海、北海和波羅的海上的風能電廠與整個北歐的消費者們連接起來。