北師大版高中英語選修八unit22environmentalprotectionsectionⅰ課時訓(xùn)練-文庫吧資料
2024-12-11 00:00本頁面
【正文】 life cycle studies and experiments across four continents and 1,634 found that some experiments had underestimated(低估 ) the speed of flowering by times and leafing by 4 times. “Across all species,the e xperiments underpredicted the speed of the advance— for both leafing and flowering — that results from temperature increases,”the study said. The design of future experiments may need to be improved to better predict how plants will react to climate change,it said. Plants are necessary for life on the are the base of the food chain,using photosynthesis(光合作用 ) to produce sugar from carbon dioxide and let out oxygen which is needed by nearly every anism on the pla. Scientists believe the world’s average temperature ha s risen by about ℃ since 1900,and nearly ℃ every ten years since 1979. So far,efforts to cut emissions (排放 ) of plawarming greenhouse gases are not seen as enough to prevent the Earth heating up beyond 2 ℃ this century — a point scientists say will bring the danger of a changeable climate in which weather extremes are mon,leading to drought,floods,crop failures and rising sea levels. is the key information the author wants to give in Paragraph 1? ’ reaction to weather could have damaging effects on ecosystems. increasing speed of flowering is beyond scientists’ expectation. change
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