Writing for post.pptVIP

Persons in the Labor force 2．4．3因果分析(Cause and Effect) 在日常生活中，为了揭示事件、行为、现象等的原因和结果，常常用到因果分析。因果分析尤其适用于科技说明文，如雨是怎么形成的?造成一个城市污染的原因是什么?人类进化的因素有哪些?等等。然而，要把原因和结果解释清楚并符合逻辑性并不是一件容易的事，因为一件事的结果可能由几方面的原因造成，而一个原因也可能引起几方面的结果。 通常可以按照以下4种方式来展开分析： (1)一因一果。这种方式最为简单，但却不常见，因为多数事物的发生不可能那么单纯。 (2)——因多果。范文l便是采用这种方法说明了气候变暖给地球上带来的一系列变化。 For the last hundred years the climate has been growing much warmer. This has had a number of different effects. Since the beginning of the 20th century, glaciers have been melting very rapidly. For example, the Muir Glacier in Alaska has retreated 2 miles in IO years. Secondly, rising temperatures have been causing the snowline to retreat on mountains all over the world. In Peru, for example, it has risen as much as 2, 700 feet in 60 years. As a result of this, vegetation has also been changing. In Canada, the agricultural cropline has shifted 50 to 100 miles northward. In the same way cool climate trees like birches and spruce have been dying over large areas of Eastern Canada. In Sweden the treeline has moved up the mountains by as much as 65 feet since 1930.The distribution of wildlife has also been affected, many European animals moving northwards into Scandinavia. Since 1918, 2 5 new species of birds have been seen in Greenland , and in the United States birds have moved their nests to the north.Finally, the sea has been rising at a rapidly increasing rate, largely due, as was mentioned above, to the melting of glaciers. In the last 18 years it has risen by about 6 inches, which is about four times the average rate of rise over the last 9, 000 years. Owning a car is very expensive; in fact, not only is buying a car expensive initially, but we must also spend a lot of money on it once we have bought it. First, we have to have the cash to buy the car, or at least to make a down payment. If its a new car, this can be a large amount! ”then,after we buy it, we have to pay a tax to get a county sticker and lic