Unit 8Focus on Global WarmingKey to the ExercisesText comprehensionI. AII. 1. T; 2. T; 3. F; 4. F; 5. F.III.1. Paragraph 2. Because global warming may be the single largest threat to our planet（the earth）. Low-lying nations could be awash in seawater, rain and drought patterns across the world could change, hurricanes could become more frequent, and El Ninos could become more intense.2. Paragraph 3. Our factories, power plants, and cars burn coal and gasoline and spit out carbon dioxide, produce methane by allowing our trash to decompose in landfills and by breeding large herds of methane-belching cattle, and release nitrogen oxide by using nitrogen-based fertilizers.3. Paragraph 4. The increased concentrations of greenhouse gases prevent additional thermal radiation from leaving the Earth, so cause the global warming.4. Paragraph 7. A slight increase in heat and rain in equatorial regions would increase vector-borne diseases such as malaria; more intense rains and hurricanes could cause more severe flooding and more deaths in coastal regions and along riverbeds; even a moderate rise in sea level could threaten the low-lying islands; hotter summers could lead to more cases of heatstroke, hospital admissions and deaths among vulnerable people with heart problems or respiratory problems.5. Paragraph 8 and 10. We can curb our consumption of fossil fuels and use technologies to reduce the emission of heat-trapping gases like carbon dioxide, methane, and nitrous oxides, and protect the forests in the world, and we can also advocate policies that will combat global warming over the long term, things like clean cars, environmentally responsible renewable energy technologies, and stopping the clear-cutting of valuable forests.IV.1. Global warming will probably be the most serious threat to our Earth, if we do not take into account of some other possible disasters, such as another world war, collision of our Earth with some small orbiting planet, or spread of incurable diseases.2. In terms of human health, the people of the poorer countries will suffer most, because their countries do not have money to protect them when climate changes.Structural analysisSub-ideas in the second part:1) the causes of the rising concentration of greenhouse gases in the atmosphere (Paragraphs 3 and 4)2) the effect of such concentration on climate change (Paragraphs 5 and 6)3) the potential threat of global warming to human health and survival (Paragraph 7)VocabularyI. Phrase1. with the exception of: except, apart from 除之外，不包括在内2. In essence = essentially, basically 本质上，根本上3. wherever possible: whenever it is possible 只要可能4. over the long term: over a long period 从长远看5. alternative = substitutable, different, replaceableII.1. focus; 2. much the same; 3. consciousness; 4. threat; 5. deserved; 6. decomposed; 7. revealed; 8. frequent.III. Word derivationFill in the blanks with the appropriate forms of the given words.1. perusal 2. intensified 3. excessive 4. speculative 5. abundance 6. inclusive 7. emits 8. locally IV.1. A; 2. D; 3. B; 4. C; 5. D; 6. A; 7. C; 8. A.V. Synonym / AntonymGive a synonym or an antonym of the word underlined in each sentence in the sense it is used.1. Synonym: mainly, basically, firstly2. Antonym: unfortunately, unluckily3. Antonym: exclude4. Synonym: part, division5. Antonym: decrease, lowering6. Antonym: unavailable7. Synonym: weak, insecure, unsafe8. Antonym: irresponsibleVI. PrefixWrite in each space one word that has the same prefix as underlined in each given word.1. centigrade centimeter 2. kilogram kilometer 3. synopsis synthetic 4. supervise superior 5. submarine submerge 6. astronaut astronomy 7. microbiology microwave 8. overwork overload Grammar ExercisesI. Complete the following sentences using the appropriate verb forms.1. began / / have had2. A: Have / talkedB: Have talked / talked3. has invented4. have / telephoned / went5. have been6. has got (gotten)7. has been8. have forgotten9. B: has goneB: About ten minutes ago.10. was / has disappeared.III.1. a. simple present form; b. “has obtained”.2. synonymous a. the speakers point of view; b. the listeners perspective.3. a. definite; b. indefinite4. a. still suffering; b. past5. a. on the way or in Italy; b. left Italy.6. a. in the morning; b. after the morning7. a. today is not finished and he may drink more; b. simply happened today.8. a. passed away; b. still living.IV.1. have had have2. have been be3. laying lying4. bore bear5. Rang Rung6. rised risen7. had hasV. Fill in the blanks with because, as, since, seeing that, for or because of.1. As / Since2. because / as3. As / Since / Seeing that4. because5. because of6. As / Since7. for8. as / becau