Unit4Globalwarminggrammar强调句课件--高中英语人教新课标选修六.pptx

演讲人：当图网; ;强调句的作用 ; ; ; ; ; ; ; ; ;1. It was a scientist called Charles Keeling, who made accurate measurements of the amount of carbon dioxide in the atmosphere from 1957 to 1997. 2. … it is the burning of more and more fossil fuels that has resulted in this increase in carbon dioxide.; 2.Rewrite each sentence with It is … that /who to give more emphasis to the underlined part. (Page 29);It is for centuries that carbon dioxide has the tendency to stay in the atmosphere while other greenhouse gases stay in the atmosphere only for a day or less. It is their very existence that low – lying countries feel is in danger from rising sea levels. It is environmentalists who have tried to stop the earth’s temperature rising.;It is future climate changes and their effects on our environment that scientists want to find out about . It is by several metres that the level of the sea could rise in the years ahead because of global warming. It is outer space that might provide us with new energy sources in the future.