Part C

　　Directions:

　　Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written carefully on ANSWER SHEET 2. (10 points)

　　One basic weakness in a conservation system based wholly on economic motives is that most members of the land community have no economic value. Yet these creatures are members of the biotic community and, if its stability depends on its integrity, they are entitled to continuance.

　　When one of these noneconomic categories is threatened and, if we happen to love it .We invert excuses to give it economic importance. At the beginning of century songbirds were supposed to be disappearing. (46) Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them, the evidence had to be economic in order to be valid.

　　It is painful to read these round about accounts today. We have no land ethic yet, (47) but we have at least drawn near the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.

　　A parallel situation exists in respect of predatory mammals and fish-eating birds. (48) Time was when biologists somewhat over worded the evidence that these creatures preserve the health of game by killing the physically weak, or that they prey only on “worthless” species.

　　Some species of tree have been read out of the party by economics-minded foresters because they grow too slowly, or have too low a sale vale to pay as imeber crops (49) In Europe, where forestry is ecologically more advanced, the non-commercial tree species are recognized as members of native forest community, to be preserved as such, within reason.

　　To sum up: a system of conservation based solely on economic self-interest is hopelessly lopsided. (50) It tends to ignore, and thus eventually to eliminate, many elements in the land community that lack commercial value, but that are essential to its healthy functioning. Without the uneconomic pats.

　　关键句翻译

　　46.科学家们贸然拿出一些看似站不住脚的证据来补救，其大意是：鸟类不能控制害虫的话，害虫就会把我们人类吃掉。

　　47.但是至少我们几乎承认了这样一种观点，那就是不管鸟类的生存对我们是否有经济利益，它们都有与生俱来的生存权利。

　　48.曾几何时，生物学家们总是重申这样的事实：这些生物通过捕食弱小的生物来维系健康的生物链，或者说它们只不过是在捕食无价值的物种。

　　49.在欧洲，生态林业较为发达，那些无商业价值的树种被视为天然森林群落的成员，应该得到合理保护。

　　50.这种体系通常忽视并最终导致很多陆地上物种的灭绝，这些物种往往是没有商业价值但却对陆地生态系统的健康运行至关重要。