The dams① aimed at saving Venice from the waves have been backed greatly. After eight years of argument, it plans to build 79 gates across three channels connecting the lagoon around Venice with the A 题目和参考答案——青夏教育精英家教网—

题目内容

The dams① aimed at saving Venice from the waves have been backed greatly. After eight years of argument, it plans to build 79 gates across three channels connecting the lagoon around Venice with the Adriatic Sea. The gates would be open most of the time but would be closed if there is a danger to the city.

The project, though, has run into fears that it could worsen Venice’s problems. The city throws waste into the lagoon, and environmentalists fear the dams will cause this pollution to become worse if there is no tide to wash it out regularly. But if there is a tide, the flow can wash away about 550 million cubic meters of the lagoon in a single day, which means that by leaving the dam open for only a few hours, the waste should be cleaned out.

Another piece of good news is that British scientists are confident that the dams will be able to face an expected rise in sea levels caused by global warming. The gates are designed to stand a 22-centimetre rise in sea levels, but many scientists expect a global rise in sea levels of 31cm by 2100.

However, Trevor Davies and Isabel Trigo from University of East Anglia believe the dams are unlikely to broken. Climate change will weaken the local storms in the Adriatic that are the main cause of flood risk. Floodwaters are also a seasonal danger in Venice, usually because of a combination of spring tides and strong winds.

Venice, which rests on wooden piles driven into boggy③ ground, has been sinking for centuries, worsening the encroachment by the sea.

Notes:

① dam n. 大坝

② lagoon n. 泻湖

③ boggy adj. 泥泞的

④ encroachment n. 蚕食

Choose the best answers according to the above:

1. Which of the following is the main idea of the text?

A. Venice will not disappear into the sea.

B. Dams are designed to protect Venice.

C. Venice are facing dangers from the tides.

D. Global warming makes Venice worse and worse.

2. If the project comes into use, the waste in the lagoon ______.

A. will be washed away by the tides B. will be sent to the higher places

C. will be carried away by workers D. will have to be reused by humans

3. According to the idea of Trevor Davies, the dams won’t be broken because ______.

A. the dams are higher than the buildings in Venice

B. there will be no tides or floods in the future

C. the climate all over the world will soon be cold

D. the storms in the Adriatic will be weaker in the future

4. According to the text, we can infer that Venice ______.

A. has been sinking for hundreds of years

B. may suffer from spring tides and strong winds

C. will be under the sea sooner or later

D. will be a city with dams around except 78 gates

CADB

解析:

1 C 主旨概括题。本篇文章的中心是说为了防止威尼斯受到海水的侵袭，科学家已经计划好了要建大坝。

2 A 细节理解题。由文章的第二段可知。

3 D 细节理解题。由文章的第四段可知。

4 B 推理判断题。由文章的第四段可推之。

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The Mekong River Commission has found no evidence the dams on the upper reaches have an influence on the water flow downstream.

The damming of river systems in the northwestern United States has had damaging effects on salmon(鲑鱼). In the spring young salmon, called smolts, drift into rivers from smaller streams. They swim with the current downstream heading for the Pacific Ocean. Before the large-scale constructions of dams(水坝), the young salmon used the strong flow from melting snows to get to the sea in between six and twenty days. It is necessary to do this because during these days the smolts’ bodies undergo the physiological changes for adaptation to salt water.
Unfortunately, the current has become very slow due to the construction of numerous dams. Companies operating the dams also intentionally slow the current. They store the water from the melting snow until the winter, when more electric power is needed. The net result is that many of the young fish do not survive the now sixty-day trip to the sea. Consequently, there are fewer adult salmon to migrate(回游) back up the rivers for breeding. When the time comes for the salmon to return, they again face the problem of dams. As fewer adult salmon are able to get back to their cool upstream water, they fail to produce a sufficiently new generation of salmon. This cycle could eventually lead to the extinction of the fish.
Attempts are being made to transport the young salmon down river by boats. However, many scientists think that this artificial method of getting the fish to the sea kills more than it saves. Another suggestion, recently proposed by environmentalists, is to increase the rate of water flow. This would be a partial（部分的） solution to the declining salmon numbers. One method of doing this would call for releasing water from upstream dam. This would speed up the downstream movement of the smolts.
Another method would be to reduce the water level in the dams for a period in the spring when the smolts are migrating downstream. This would also increase the flow rate temporarily without requiring large amounts of water and, thus, enable the young salmon to move downstream faster. Unfortunately, both of these proposals have met with criticism from the power companies, which strongly suggests the uncertain fate of the salmon in the region.
76. What’s the main topic of the passage?
A. The failure of adult salmon to reproduce.
B. The importance of smolts returning upstream.
C. The need for smolts to reach salt water quickly.
D. The harm caused to salmon by river damming.
77. The passage discusses all of the following methods of dealing with salmon issue EXCEPT _____.
A. carrying the fish in boats
B. allowing water to be released from upstream dams
C. dropping water levels in dams
D. breeding salmon
78. In paragraph 3, what does the author mean by the statement that many scientists think that this artificial method of getting the fish to the sea kills more than it saves?
A. Saving fish is artificial.
B. More fish die when transported than would die otherwise
C. Artificial methods of transportation give salmon the chance to get adapted to salt water.
D. The sea kills more fish than are saved by transportation.
79. Which of the following statements would the author most probably agree with?
A. The salmon problem is likely to continue.
B. A solution to the salmon problem will be found in the near future.
C. Salmon will be extinct very quickly.
D. The government should step in and provide a way out.

The Mekong River Commission has found no evidence ______ the dams on the upper reaches have an influence on the water flow downstream．

A．which 　　B．that 　　C．where 　　　 D．what

The Mekong River Commission has found no evidence the dams on the upper reaches have an influence on the water flow downstream.

A．that B．which C．where D．what

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