D. it will discourage an argument about stricter rules 61. It can be inferred from the last two paragraphs that ________. A. the European politicians’ advice is perfect B. customers’ demands play a role in setting standards
C. lock-in is caused by firms’ storing information in their own centres D. Google enables users to provide services and move data
62. Which of the following sayings can best express the main idea of the passage? A. Everything has its time and that time must be watched. B. The grass looks greener on the other side of the fence. C. A candle lights others and consumes itself.
D. Every white has its black, and every sweet has its sour. 【答案】 58.A 59.B 60.C 61.B 62.D 【解析】
考点：科技类短文阅读。
C
Scientists have exactly discovered the set of brain cells involved in making risky decisions, and have been able to control them in rats using targeted light. By changing the activity of the cells they were able to change the behaviour of risk-taking rats to avoid risk, hinting the approach could in future be used to treat people with impulse (冲动) control problems.
Risk-taking is a key part of survival, knowing when to take a chance could pay off—such as moving to a new area to look for food when pickings are slim.
While all animals need an element of risk, the preference towards it varies between individuals. Researchers found this variation, which determines how risk-averse an individual is, is regulated by brain cells in a region of the brain called the nucleus accumbens. This cluster of neurons releases the neurotransmitter dopamine, which regulates the brain’s reward and pleasure centres.
Previous studies have shown that in patients with Parkinson’s disease, taking medication which blocks specific dopamine receptors (DR2) (受体) leads to increased gambling (赌博) behaviour and risk taking behaviour. In studies with rats, researchers were able to use a technique called optogenetics (光遗传学)—which uses light
sensitive proteins to change the activity of cells—to modify cells with DR2 in the nucleus accumbens.
Rats were trained to choose one of two levers, offering them a choice between a “safe” or “risky” choice. The safe option resulted in a small, but consistent amount of a sugar water treat. But the risky choice consistently delivered smaller amounts of sugar water, with the occasional large pay off—essentially encouraging the animals to gamble for a bigger prize. Around two-thirds of the animals weren’t keen on risk, opting for the safe option, but the remaining third were risk-seekers. Brain scans of the animals showed that those with low levels of DR2 consistently went for the gamble.
But using pulses of light to stimulate (刺激) the DR2 cells and improve their activity could cause the risk-takers to play it safe and opt for the guaranteed but less rewarding option. Once the light-pulses stopped, the risk-takers returned to their gambling strategy.
In the risk-averse animals, stimulating the same cells had little to no effect.
Professor Karl Deisseroth, of Stanford University in California, said: “Humans and rats have similar brain structures involved.”And we found a drug known to increase risk preference in people had the same effect on the rats. So every indication is that these findings are relevant to humans. “Risky behavior has its moments where it’ s valuable. As a species, we wouldn’t have come as far as we have without it.”
63. The variation in people’s preference towards risks is directly regulated by ________. A. nucleus accumbens B. light sensitive proteins C. neurons D. dopamine 64. From the experiment with rats, we can conclude that ________. A. the lack of DR2 cells results in a safe option B. the levels of DR2 have little to do with their choices C. the high levels of DR2 can make animals avoid risks D. the risky choice is a less rewarding option
65. The underlined words in Paragraph 7 most likely mean the animals that are ________. A. willing to take big risks C. fond of gambling strategy
B. reluctant to take risks D. afraid of receiving stimulation
66. What can be inferred from what Professor Karl Deisseroth said? A. Humans and rats differ in their preference for risk-taking. B. Too much risk-taking can do more harm than good.
C. Risk-taking can be used to treat people with impulse control problems.
D. Risk-taking is a means of survival and brings higher returns to humans. 【答案】 63.D 64.C 65.B 66.D 【解析】
试题分析：科学家发现脑细胞参与决策风险。通过改变细胞的活动，可以避免冒险的行为。但是冒险也使得人类进步。
63.D 细节理解题。根据第三段This cluster of neurons releases the neurotransmitter dopamine, which regulates the brain’s reward and pleasure centres.可知，人们对风险的偏好程度直接受代多巴胺的控制，故选D。 64.C 推理判断题。根据Brain scans of the animals showed that those with low levels of DR2 consistently went for the gamble.可知，DR2含量高可以避免冒险。故选C。
65.B 词义推测题，根据In the risk-averse animals, stimulating the same cells had little to no effect. 前面的描述告诉读者，刺激DR2细胞对控制冒险有帮助，这里应该是说明例外的情况，不愿意冒险的动物，刺激相同的细胞也没有效果，故选B。
66.D 推理判断题。根据最后一句话Risky behavior has its moments where it’ s valuable. As a species, we wouldn’t have come as far as we have without it可知，没有冒险人类就不会进步，故选D。 考点：科普类短文阅读。
D
Wisconsin has long been home to incredibly successful research and innovation thanks to our famous academic research institutions and some of the brightest scientific minds. From discovering how Vitamin D can best be absorbed, to unlocking the potential of stem cells, Wisconsin has pioneered remarkable breakthroughs in science that have improved health, saved lives and created jobs. These scientific breakthroughs have not only led to life-saving medical technologies but also have fostered (培育) a strong power in Wisconsin economy.
Across America, groundbreaking research supported by the National Institutes of Health (NIH) alone adds millions of dollars to our economy every year. In fact, NIH funding generated an estimated $58 billion in economic output nationwide in 2014. NIH funding spurs economic growth by supporting jobs in research and by generating
