题型:阅读理解 题类:常考题 难易度:普通
湖南省衡阳市第一中学2018-2019学年高二上学期英语期末考试试卷
When it comes to climate change, there are always some new, terrifying consequences to worry about—like ancient viruses and bacteria coming from the ice as the earth warms. Unfortunately, researchers fear we may see more of this in the future.
Some of these viruses and bacteria may have been trapped for thousands of years, and it's not even totally clear yet what they are, let alone what kind of damage they might have.
Researchers have met complex “giant viruses” in the melting permafrost(永久冻土) of Siberia. One such virus, 30,000 years old, was still infectious when it was discovered in 2015, though it posed no danger to humans. It turns out that permafrost is excellent at preserving bacteria and viruses that are temporarily inactive, and then become reactivated with warming.
Scientists have discovered Spanish flu viruses in dead bodies buried in 1918 in the Alaskan tundra (冻原). When close to half of the population of a Siberian town in the 1890s died of smallpox (天花), their bodies were buried in the permafrost along the Kolyma River. The banks of that river are now beginning to wear away amid global warming, the BBC reports.
In Siberia in August 2016, some 100 people and 2,300 deer were infected with anthrax(炭疽) in the first outbreak in the area since 1941. One boy died from the disease. Scientist believed the anthrax had been trapped in the body of a long-frozen dead deer and became active during particularly hot summer of 2016, releasing the bacteria cells into the environment.
But even in warmer climates, rising temperatures can help grow and spread dangerous diseases. Over a decade ago, researcher Paul Epstein prophesied the possible spread of mosquito-born illnesses as a result of climate change. “Mosquitoes are sensitive to temperature changes,” he said. “Warming speeds up their rates of reproduction and the number of blood meals they take, makes their breeding (繁殖) season long, and shortens the maturation period for the germs they spread” — all of which makes them more efficient at spreading disease.
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