《2024年绿色通道45分钟课时作业与单元测评英语选择性必修第三册》

                                                                   B
Alaska's Arctic lakes now freeze later and melt earlier inthe year than in 1950, leaving them easy to suffer water loss from evaporation(蒸发)and possibly adding to local warming, a new study finds. The winter ice season near Barrow, Alaska, is shorter than that in 1950, researchers reported on 30 January in the journal The Cryosphere.
　　Lake ice is also thinner each winter. The scientists surveyed 402 lakes on the North Slope, where permafrost and shallow lakes dominate the area. In 2011, the lake ice was 38 percent thinner than in 1950, and 22 percent fewer lakes froze through to their bottoms.
　　“When we saw the actual numbers we were shocked at how dramatic the change has been,” lead study author Cristina Surdu, professor of the University of Waterloo in Canada, said in a statement. Surdu and her co - authors analysed the changes in lake - ice thickness and ice cover with satellite images and climate model simulations.
　　The climate models suggest the Arctic lakes froze almost 6 days later and broke up about 18 days earlier in the winter of 2011 compared with that in the winter of 1950. “The changes in ice and the shortened winter affect Northern communities that depend on ice roads to transport goods,” Surdu said. For example, every winter, oil companies build roads over frozen lakes to carry supplies to Prudhoe Bay.
　　“The dramatic changes in lake ice may also contribute to further warming of the entire region, because open water in lakes contributes to warmer air temperatures,” Surdu said. The
Arctic is warming twice as fast as the rest of the planet, for reasons that may include its layered atmosphere, which traps heat, and the loss of sea ice and snow cover, which help reflect the sun's energy when present.

5. What is the North Slope dotted with?
A. Thick forests.
B. Numerous lakes.
C. Green grasslands.
D. Fertilised farmlands.
6. According to the text, the great changes of
Alaska's Arctic lakes________.
A. are totally beyond Surdu's expectations
B. are completely within Surdu's expectations
C. come as no surprise to Surdu and her co - authors
D. come as a great excitement to Surdu
7. How many days was the winter ice season of
Arctic lakes in 2011 shorter than that in 1950?
A. 6 days.　　　　　　B. 12 days.
C. 18 days.　　　　　　D. 24 days.
8. What does the text mainly tell us?
A. Arctic lakes now freeze earlier and melt later.
B. Alaska's local warming is decreasing sharply.
C. Arctic lakes are losing ice.
D. Arctic lakes hold more fresh water than before.

答案： 5.B 细节理解题。根据第二段第二句可知，阿拉斯加北坡布满了大量的湖泊。故选B。
6.A 细节理解题。根据第三段第一句中的“we were shocked at how dramatic the change has been”可知，湖泊的变化完全超出了苏尔杜的预期。故选A。
7.D 细节理解题。根据第四段第一句可知，与1950年相比，2011年北极湖泊结冰的时间晚了6天，融化的时间早了18天。由此可知，北极湖泊2011年的结冰季比1950年一共短了24天。故选D。
8.C 主旨大意题。通读全文可知，本文主要介绍了北极湖泊冰期缩短，A、B两项均不符合文意，而D项在文中未提及。故选C。

       Compared with the obvious environmental issues we hear about every day, littering(乱丢废物)is often taken lightly. But it's more severe than we may think.
       1.___ This seems to be a completely harmless action due to the fact that it's part of a fruit−right? Actually, no. A banana peel(皮) can take up to two years to decompose(分解), and with a third of drivers admitting to littering while driving, that's a whole lot of banana peels, or much worse. An orange peel or a cigarette butt has a similar decomposing term to that of a banana. But tin and aluminium(铝) cans last up to 100 years.2___
       It's true that longer−lasting materials will damage the environment and its animals for longer.3.___ For example, despite its fairly short decomposing term, more than 120 tons of cigarette−related litter is discarded(丢弃) in the UK every day. Besides, our annual littering, which has increased by 500 percent since the 1960s, has caused the UK's rat population to increase by 60 million.
       It's not a cheap habit either:4____ So, it's not surprising that if caught littering you could face a £20,000 fine or even jail time and, if you throw away something dangerous, the court could give you five years to serve. The punishments might seem severe. 5_____ So we still have some way to go in making sure people follow the rules.
       To take back our beautiful countryside and cities we need to do more than simply not littering. We need to truly care more about the world around us.

A. Banana peels are among the most frequent littered stuff.
B. But fear of the environmental impact of litter is on the rise.
C. Imagine throwing a banana peel out of your car while driving.
D. And plastic bottles last forever, as do glass bottles and plastic bags.
E. The UK taxpayers pay £500 million in order to keep our streets clean.
F. However, among the reported cases only 2,000 out of 825,000 were punished.
G. But we can't simply measure the seriousness of a certain type of rubbish by its lifetime.

答案： 1.C 根据下文的“This seems to be a completely harmless action due to the fact that it's part of a fruit - right?”可知，空处应谈及一种看似无害的行为。C项“Imagine throwing a banana peel out of your car while driving.”符合语境。下文中的“while driving”与C项中的“while driving”一致。故选C。
2.D 根据上文的“An orange peel or a cigarette butt has a similar decomposing term to that of a banana. But tin and aluminium cans last up to 100 years.”可知，此处在介绍不同的垃圾分解所需要的时间。D项“And plastic bottles last forever, as do glass bottles and plastic bags.”符合语境，与上文构成递进关系。故选D。
3.G 根据上文的“It's true that longer - lasting materials will damage the environment and its animals for longer.”及空后的例子可知，空处与上文构成转折关系。G项“But we can't simply measure the seriousness of a certain type of rubbish by its lifetime.”承接上文话题，并在语义上与上文构成转折，符合语境。故选G。
4.E 根据上文的“It's not a cheap habit either”可知，空处会涉及金钱。E项“The UK taxpayers pay £500 million in order to keep our streets clean.”符合语境，其中的“pay £500 million”与上文中的“not a cheap habit”呼应。故选E。
5.F 根据上文的“The punishments might seem severe.”以及下文的“So we still have some way to go in making sure people follow the rules.”可知，空处内容应与上文构成转折，并与下文构成因果关系。F项“However, among the reported cases only 2,000 out of 825,000 were punished.”符合语境。故选F。