第四章单元测试
Passage 1
Directions: The passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter.
Living in an urban area with green spaces has a long-lasting positive impact on people’s mental well-being, a study has suggested. UK researchers found moving to a green space had a sustained positive effect, unlike pay rises or promotions, which only provided a short-term boost. Co-author Mathew White, from the University of Exeter, UK, explained that the study showed people living in greener urban areas were displaying fewer signs of depression or anxiety. “There could be a number of reasons,” he said, “for example, people do many things to make themselves happier: they strive for promotion or pay rises, or they get married. But the trouble with those things is that within six months to a year, people are back to their original baseline levels of well-being. So, these things are not sustainable; they don’t make us happy in the long term. We found that for some lottery (彩票) winners who had won more than ￡500,000 the positive effect was definitely there, but after six months to a year, they were back to the baseline.”
Dr. White said his team wanted to see whether living in greener urban areas had a lasting positive effect on people’s sense of well-being or whether the effect also disappeared after a period of time. To do this, the team used data from the British Household Panel Survey compiled by the University of Essex.
Explaining what the data revealed, he said: “What you see is that even after three years, mental health is still better, which is unlike many other things that we think will make us happy.” He observed that people living in green spaces were less stressed, and less stressed people made more sensible decisions and communicated better.
With a growing body of evidence establishing a link between urban green spaces and a positive impact on human well-being, Dr. White said, “There’s growing interest among public policy officials, but the trouble is who funds it. What we really need at a policy level is to decide where the money will come from to help support good quality local green spaces.”
Passage 2
Directions: The passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter.
California has been facing a drought for many years now, with certain areas even having to pump freshwater hundreds of miles to their distribution system. The problem is growing as the population of the state continues to expand. New research has found deep water reserves under the state which could help solve their drought crisis. Previous drilling of wells could only reach depths of 1,000 feet, but due to new pumping practices, water deeper than this can now be extracted (抽取). The team at Stanford investigated the aquifers (地下蓄水层) below this depth and found that reserves may be triple what was previously thought.
It is profitable to drill to depths more than 1,000 feet for oil and gas extraction, but only recently in California has it become profitable to pump water from this depth. The aquifers range from 1,000 to 3,000 feet below the ground, which means that pumping will be expensive and there are other concerns. The biggest concern of pumping out water from this deep in the gradual settling down of the land surface. As the water is pumped out, the vacant space left is compacted by the weight of the earth above.
Even though pumping from these depths is expensive, it is still cheaper than desalinating (脱盐) the ocean water in the largely coastal state. Some desalination plants exist where feasible, but they are costly to run and can need constant repairs. Wells are much more reliable sources of freshwater, and California is hoping that these deep wells may be the answer to their severe water shortage.
One problem with these sources is that the deep water also has a higher level of salt than shallower aquifers. This means that some wells may even need to undergo desalination after extraction, thus increasing the cost. Research from the exhaustive study of groundwater from over 950 drilling logs has just been published. New estimates of the water reserves now go up to 2,700 billion cubic meters of freshwater.
答案:0
