【issue121 gter三月机考小组090117的第一次作业】

slipingUID: 2584903

121. "At various times in the geological past, many species have become extinct as a result of natural, rather than human, processes. Thus, there is no justification for society to make extraordinary efforts, especially at a great cost in money and jobs, to save endangered species." 在过去不同的地质时期，很多物种的灭绝都是自然因素造成，而并非人类行为。所以，社会没有理由花费很大的人力物力去拯救濒临灭绝的物种
It is true that many species have become extinct due to the natural factors in the geological past, but this reason cannot to serve as the critical factors to the extinction of most species today. Nowadays the behaviors of human beings have taken the place of natural factors. So it is inevitable to cost a great deal of money and jobs to save the endangered species.

admittedly, natural factors have play an important role in the extinction of species at the various times in the geological past. To illustrate it the following examples can be useful. As we all know, dinosaurs exist in the world at one time. But they have extinct 650 million years ago. The most authority explanation about it is a meteorite hit the earth. Result in a big exploring which throw the dust to the atmosphere and form the fig which covers the whole atmosphere. Accordingly, photosynthesis cannot go on as before. So the dinosaurs have no choices but to disappear from the world. The same goes to the mammoth, who extinct during the Ice Age. We can safely claim that it is the natural factors lead to the species dying out at various time in the geological past.

Without denying that keep the species diversity will return more to our human beings. It is known to everyone that human beings cannot live in the world alone. Since our human being have no capability to produce food and oxygen which are basis to life. It is very the various specious provide these things. Not only supplying us with this but also with the environment we live in. Various plants contribute to conserve of both moisture and soil so that the floods will not happen and we can live a better life. It is both the various kinds of species and human being consist of a balanced ecological system. To get a better future, the cost to protect the specious is needed.


Obviously, human being have threaten the species diversity. It is reported that the area of woods in Latin African have reduced to 52percent and the plant species have decreased by 15percent--13600 species are included just due to the forest is destroied people in
order to obtain more arable land in recent century. The other major behavior which is threat to the specious is that human being gun for the precious specious. For they could benefit from it,
by selling them to serve as food. Tigers may be the victims who are pay more attention to. For they have stand at the edge of extinction. And some specious are endangered because of the polluted environment. In short, all this happen just as a result of improper behaviors of human beings, so it is our duty to protect them from dying out however money and job it need.

Without the kinds of species accompanying our human beings to exist in the world we cannot live a good life either. Therefore, there is no reason for society to deny costing money and jobs to saving endangered species.


字数（510）  作者：sliping      修改者：sherman