简答题：根据下面资料，回答题 Read the following text carefully and then transl

根据下面资料，回答题
Read the following text carefully and then translate the underlined segments into Chinese．Your translation should be written clearly on ANSWER SHEET．The world' s environment is surprisingly healthy．Discuss．If there were an examination topic,most students would tear it apart, offering a long list of complaints from local smog (烟雾) toglobal climate change, from the felling (砍伐) of forests to the extinction of species．The listwould largely be accurate, the concern legitimate．56) Yet the students who should be given the highest marks would actually be those who agreed with the statement．The surprise is how good things are, not how bad．
After all, the world' s population has more than tripled during this century, and world outputhas risen hugely, so you would expect the earth itself to have been affected．Indeed, if peoplelived, consumed and produced things in the same way as they did in 1900 (or 1950, or indeed1980), the world by now would be a pretty disgusting place, smelly, dirty, toxic and dangerous．
But they don' t．57) The reasons why they don' t, and why the environment has not been ruined, have to do with prices, technological innovation, social change and government regulation in response to popular pressure．That is why today' s environmental problems in the poor countriesought, in principle, to be solvable．Raw materials have not run out, and show no sign of doingso．Logically, one day they must: the planet is a finite place．Yet it is also very big, and man isvery ingenious．58) What has happened is that every time a material seems to be running short, the price has risen and, in response, people have looked for new sources of supply, tried to find ways to use less of the material, or looked for a new substitute．
For this reason prices for energy and for minerals have fallen in real terms during the century．Thesame is true for food．59) Prices fluctuate, in response to harvests, natural disasters and political instability; and when they rise, it takes some time before new sources of supply become available．But they always do, assisted by new farming and crop technology．The long term trend has been downwards．
60) It is where prices and markets do not operate properly that this benign( 1~[~ ) trend begins to stumble, and the genuine problems arise．Markets cannot always keep the environmenthealthy．If no one owns the resource concerned, no one has an interest in conserving it or fosteringit: fish is the best example of this．
第56题答案为