四、通过假设进行正反论述。

　　Then, since the transportation system is the lifeline of a country’s economic activities, its paralysis would lead to the disintegration of the economy, either industry of farming or daylife. Suppose all the means of transportation were halted for lack of oil, factories with insufficient raw materials would have to close, workers would be out of work, and ripe farm crops would have to stay in the fields at the mercy of rain and storms. People would try to store food and the price of all commodities would go up. If we take those power stations run by oil into account, situations would become even worse. In this sense, oil decides the fate of the whole economy and that of the government。

　　通过假设得出了一系列的可怕的后果，最后再得出结论，这样的结论是发人深省，当然也是最能引起人们广泛重视的。

　　五、换种说法，换而言之。

　　The computer technology has no doubt at all replaced most of function, that is, we can read books from the academic database; newspapers and publishes from almost everywhere, this means that we do not need many hard copies and environment friendly for the earth. However I am not so much convinced that public libraries can replace other functions that we need other than providing information or books。

　　换而言之就是换种方式去解释，使解释更加具体直观话，因而更能被理解并接受。

                                                                                                                       摘自新浪教育频道