课后限时作业8

1、课后限时作业(八)限时/50分钟.阅读理解Plants are flowering faster than scientists predicted in reaction to climate change, which could have long damaging effects on food chains and ecosystems.Global warming is having a great effect on hundreds of plant and animal species around the world, changing some living patter

2、ns, scientists say.Increased carbon dioxide (CO2) in the air from burning coal and oil can have an effect on how plants produce oxygen, while higher temperatures and changeable rainfall patterns can change their patterns of growth.“Predicting species reaction to climate change is a major challenge i

3、n ecology，” said the researches of several US. universities. They said plants had been the key object of study because their reaction to climate change could have an effect on food chains and ecosystem services.The study, published on the Nature website, uses the findings from plant life cycle studi

4、es and experiments across four continents and 1,634 species. It found that some experiments had underestimated(低估) the speed of flowering by 8.5 times and leafing by 4 times.“Across all species, the experiments underpredicted the speed of the advancefor both leafing and floweringthat results from te

5、mperature 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 Earth. They are the base of the food chain, using photosynthesis(光合作用)to produce sugar from carbon dio

6、xide and water. They let out oxygen which is needed by nearly every organism on the planet.Scientists believe the worlds average temperature has risen by about 0.8 since 1900, and nearly 0.2 every ten years since 1979.So far, efforts to cut emissions(排放) of planetwarming greenhouse gases are not see

7、n as enough to prevent the Earth heating up beyond 2 this centurya point scientists say will bring the danger of a changeable climate in which weather extremes are common, leading to drought, floods, crop failures and rising sea levels.语篇导读本文为说明文，介绍了全球变暖的气候环境会让植物提前生长开花，进而影响整个食物链及生态系统。1What is the ke

8、y information the author wants to give in Paragraph 1?APlants reaction to weather could have damaging effects on ecosystem.BThe increasing speed of flowering is beyond scientists expectation.CClimate change leads to the change of food production patterns.DFood chains have been seriously damaged beca

9、use of weather.解析 B细节理解题。根据第一段可知，作者是要告知读者植物开花的增速超出了科学家的预期，故选B项。2What can we learn from the study published on the Nature website?APlants flowering is 8.5 times faster than leafing.BThere are 1,634 plant species on the four continents.CScientists should improve the design of their experiments.DThe ex

10、periments failed to predict how plants react to climate change.解析 C推理判断题。根据第五段第二句可推出，对于植物所设计的实验应该有所改进，故选C项。3Why do scientists pay special attention to the study of plants?ABecause they can prove the climate change clearly.BBecause they are very important in the food chains.CBecause they play a leadi

11、ng role in reducing global warming.DBecause they are growing and flowering much faster than before.解析 B细节理解题。根据第四段第二句可知，植物对气候变化的反应对整个食物链和生态系统都至关重要，故选B项。4What can be inferred from the last two paragraphs about the worlds temperature?AIt has risen nearly 0.2 since 1979.BIts change will lead to weather

12、 extremes.CIt is 0.8 higher in 1979 than that of 1990.DThe rise of the temperature needs to be controlled within 2 in this century.解析 D推理判断题。根据最后一段可知，如果本世纪地球变暖超过2，便会出现极端天气，由此可推出，这个世纪地球温度的上升需要控制在2的范围之内，故选D项。.完形填空There was once a little grey planet. It was very 1 . The people living there hadnt looked

13、 after it, though they had all the 2 you could ever need because of the rapid development of technology.They had polluted the whole planet so seriously with 3 that there were no plants or wild animals 4 .One day, a little boy was walking on the planet when he passed a cave and 5 a small red flower i

14、nside.The flower was very 6 almost dying, so the boy 7 dug up the flower with roots, soil and everything.Then he started 8 a place where he could look after it.He searched all over the planet, but everywhere was so 9 that there was no place for the flower to live.Then he looked up at the 10 and saw

15、the moon.“Maybe the flower can 11 there，” thought the boy. 12 the little boy put on his astronaut suit, and climbed into a 13 . He put the little red flower in the back, and they went to the moon.Far from all that pollution, the flower started to 14 . The flower was so 15 cared for that it started p

16、roducing seeds soon, 16 others.Before long, flowers completely 17 the moon, which looked very 18 . The earth on which we live has also been 19 in a very bad way.If we dont look after it, maybe someday we will also only be able to plant flowers on the moon.Do you want that day to 20 ？1A.movedBsadCsur

17、prised Dpretty2A.food BspaceCinventions Dskills3A.air BwaterCsmoke Drubbish4A.needed BstoredCprotected Dleft5A.picked BthrewCnoticed Dtasted6A.sick BluckyCfresh Dstrange7A.suddenly BcarefullyCeasily Dhopefully8A.taking over Blooking throughCmaking up Dlooking for9A.dirty BwetCdeep Dquiet10A.land Bmo

18、untainCforest Dsky11A.stay BsurviveCfight Dlove12A.So BButCBecause DOnce13A.boat BcarCspaceship Dtrain14A.shine BargueCgrow Dstand15A.calmly BwellCgradually Dnormally16A.giving birth to Btaking care ofClooking down upon Dtaking control of17A.cleaned BadmiredCcovered Ddestroyed18A.wide BroundCbright

19、Dbeautiful19A.supported BpollutedCdivided Dhidden20A.return BdisappearCcome Ddevelop语篇导读本文为一则童话故事，告诫我们要保护环境、爱护地球。1解析 B根据下文的描述可知，那个星球污染非常严重，可推断那个星球很伤心(sad)，故选B项。2解析 C根据空后的because of the rapid development of technology可推知，此处是指那个星球上的发明(invention)，故选C项。3解析 D他们把那个星球严重地污染了，污染环境的应该是垃圾(rubbish)，故选D项。4解析 D星球

20、已被污染，所以植物和野生动物都无法存活了，也就是说任何的野生动植物都没有被留下(leave)，故选D项。5解析 C根据语境可知，此处是指男孩经过一个洞的时候，看到(notice)了洞里的一朵花，故选C项。6解析 A根据空后的almost dying可知，小花病得厉害，sick符合语境，故选A项。7解析 B小花就快死了，小男孩应该是非常小心地(carefully)把它挖出来，故选B项。8解析 D根据语境可知，小男孩想找个地方把小花重新栽种，以便照顾它。take over接管；look through看穿，游览；make up编造，弥补，化妆；look for寻找，故选D项。9解析 A根据上文可知

21、，那个星球上到处都很脏(dirty)，故选A项。10解析 D根据小男孩看到了月亮可知，他抬头看天空(sky)，故选D项。11解析 B根据语境可知，小男孩心想或许小花可以在月亮上存活(survive)，故选B项。12解析 A小男孩心想或许小花可以在月亮上存活，所以(so)他准备去月球，故选A项。13解析 C小男孩要去月球，所以他穿上航空服，登上了宇宙飞船(spaceship)，故选C项。14解析 C到了月球上，环境变好了，小花开始生长(grow)，故选C项。15解析 B根据下文的it started producing seeds soon可知，小花被照顾得很好(well)，故选B项。16解析

22、A根据语境可知，此处讲的是小花开始繁衍，giving birth to繁殖；take care of照顾；look down看不起；take control of控制，故选A项。17解析 C小花迅速繁衍，很快就覆盖(cover)了整个月球，故选C项。18解析 D月球被花儿覆盖了，看起来非常漂亮(beautiful)，故选D项。19解析 B此处是指我们的地球也被很严重地污染(pollute)了，故选B项。20解析 C地球也被很严重地污染了，或许有一天我们也只能在月球上种花了，作者问我们：真的希望那一天到来(come)吗？，故选C项。.语法填空Throughout history, the Chi

23、nese nation has constructed 1. (thousand)of magnificent bridges, 2. ， of course, have become one of the marks of ancient Chinese civilization.The Guangji Bridge, 3. (know) as the first opening bridge in the world, is one good example of them. It 4. (lie) in the eastern suburb of Chaozhou, China, acr

24、oss the Han River for over 800 years, which at first was 5. (simple) a boat bridge built in 1170 AD. in Southern Song Dynasty with the 6. (long) of 518 meters.Later construction of piers and framework started from both banks of the river on which it was fixed, and it took a total of 200 years 7. (co

25、mplete) the Guangji Bridge with a floating section of 18 supporting wooden boats in between the two beamed sections. When necessary, the floating section can be unlocked for the passage of big boats, which is really 8. imaginative invention in bridgebuilding history. There are two iron cows standing

26、 at both ends of the bridge, 9. the hope of protecting the bridge from the flood damage. 10. makes the bridge particularly outstanding is that its two beamed sections resemble waterside streets with 24 different styles pavilions and towers for doing business, which become a special view on the bridg

27、e.语篇导读本文为说明文。在历史上，中华民族曾经建造了许多壮丽的桥梁，这些桥梁是中国古代文明的标志。其中位于潮州的广济桥就是一个典型代表。1thousands解析 考查固定搭配。句意：在历史上，中华民族曾经建造了成千上万座壮丽的桥梁，当然，这些桥梁已成为中国古代文明的标志之一。thousands of数以千计的。2which解析 考查引导词。分析句子结构可知，空处引导非限制性定语从句，修饰先行词bridges, 从句中缺少主语，故填which。3known解析 考查非谓语动词。分析句子结构可知，句中已有谓语，此处应用非谓语动词形式；know与逻辑主语The Guangji Bridge之间是动宾关系，故用过去分词known作后置定语。4lies解析 考查时态和主谓一致。主语It是单数，而且描述的是一般事实，故用一般现在时。5simply解析 考查词性转换。空处在句中作状语，应用副词，故填simply(仅仅；只不过)。6length解析 考查词性转换。空前为定冠词，空后为介词，因此空处应用名词。7to complete解析 考查非谓语动词。此处为“It takes/took (sb) some time to do sth”结构，it作形式主语，真正的主语是后面的动词不定式。8an解析 考查冠词。此处泛指“一项发明”，且imaginative以元音音素开头，故填不定冠词an。