(2)归纳现状
(3)第一个原因
(4)第二个原因
(5)第三个原因
(6)重申造成现状的最重要原因
Pollution
 Most of us today (recognize that environmental pollution has been a greatly serious problem. lots of plants trees corps are destroyed by bad air. many fish die of poisonous water. thousands of people die from eating poisoned fish or breathing in gas. therefore, environmental pollution should be responsible for these diseases that are disabling, or bringing death not only to human beings, but also to wild life.)From above, we can find that the reasons why (environment are polluted more and more seriously)are as follows.
 the primary reason, I think, is (the reason of harmful substances into environment. for example, to prevent insects, farmers make use of great amounts of insecticides, so as to have bumper harvests. however, they pollute air, water and land ).
Second,(the gas coming from the car engines and factories also make environment polluted badly ). the third reason actually is (the result of a growing population in the world. everyday, so much litter and waste are poured out from houses, also pollute the environment ). The significance for (controlling pollution) noted that it`s high time that more effective measures should be taken. Therefore, (new laws should be passed to limit the amount of pollutants from factories. moreover, in the households, there is an obvious need to reduce litter and waste. let`s make our good efforts, and the world will be a safer place to live for us).
(I)说明原因型模块(5)
These days we often hear that (1).It is common that (2). Why does such circumstance occur in spite of social protects? For one thing, (3).For another, (4). What is more, since (5),it is natural that (6 ).To solve the problem is not easy at all, but is worth trying. We sh