1、人教课标版 高二选修6Unit 4Discovering useful words and expressions (P28)Go over the new words and phrases in the previous sections. Then complete each sentence with one of those new words or phrases.21. Charles Keeling collected _on the carbon dioxide content in the atmosphere over a forty-year period. He fo
2、und that the amount of carbon dioxide _ increasing during that time.datakept on2. Although we are burning coal in huge _ every year, we wont _ of it for centuries.3. If the amount of greenhouse gases continues to _, we could be facing a global _ .quantitiesrun outbuild upcatastrophe4. Many scientist
3、s believe that global warming has _ through the burning of fossil fuels. come about5. The _ of a rising sea level would be widespread flooding.consequence6. On the whole the warming of the earth is a _ that causes great concern.7. The _ shows temperature changes during the 20th century.8. One hectar
4、e of forest can absorb 23 tons of carbon dioxide _ year.phenomenongraphper9. The washing machine uses too much energy, but _ we buy a more economical one, it would still use too much water.10. The car accident on the main road yesterday _ one drivers death.even if resulted inI. 代词 it a. 用作人称代词, 代替前文
5、提到的事物。My watch is missing. I cant find (it) anywhere. Her father has gone abroad. Have you heard about (it)? b. 代替指示代词this, that。Whats this? (Its) a computer. Whose pen is that? Its mine.c. 表示时间、天气、距离、季节等。Its time for lunch.Its getting warmer and warmerIts forty years since my hometown was liberated. Its summer now. How far is it from here to theII. 引导词： a. 作形式主语, 代替由不定式, 动名词或从句表示的真正主语。其基本句型为： It (形式主语) +adj. + to+ v. It (形式主语) +adj. + that (subject (主语)+v. )
