答案及解析

　　71.A【解析】由A中的第一段最后一句话“It assesses the impact of potential feature global climate change on agriculture and the need to sustain agricultural growth…”可知。

　　72.A【解析】由A中的第二段“...to illustrate how environmental quality can be included formally in measures of national income，social welfare and sustainability.”可知。

　　73.B 【解析】由B中的第一段“Global environmental problems arise out of the accumulated impacts from many years’ and many countries’ economic development.”可知。

　　74.B【解析】由B中的第一段“...and global biodiversity is being lost by reason of thousands of years of habitat conversions.”可知。

　　75.C【解析】由c中的第二段“…a substantial agriculture sector，which contributes to deforestation，the erosion of the top soil and desertification.has led to extreme pressures on the environment and….”可知。

　　76.D【解析】由D中的第二段“The author argues that pollution is con-trolled by increasing the relative price of the polluting goods in the production process”可知。

　　77.C【解析】由C中的第一段最后一句话“This source book…and provides policy advice，including the use of clean technologies and environmentally sound production techniques，….”可知。

　　78.A 【解析】由A中的最后一句话“…take on an economy—wide perspective to draw lessons for agriculture，trade，land use and tax policy.”可知。

　　79.B 【解析】由B中的第一段“The ozone layer is threatened by chemical emissions;the climate is endangered from fossil and deforestation….”可知。

　　80.D【解析】由D中的第二段“In the second part，the discussion is extended to include the possibilities of preventing or abating emissions in relation to three models:...”可知。

　　Section IV Writing(计25分。权重25%)

　　One possible version:

　　For most of us today, television is our main source of news. According to a questionnaire on the way of getting news, nearly 72 percent of the people watch TV ,and only 12 percent read newspapers for daily news. Although television news excels in bringing into our living room dramatic events of singular importance, space craft launchings, natural disasters, record-breaking sports events, presidential inaugurations, wars, murders and so on, it cannot cover important stories in the depth they may deserve because of its time limitations. Regardless of the complexity or significance of an event, it somehow must be fitted into a prescribed number of minutes. On the other hand, while the newspaper cannot compete with television visually, for example, a war is often best communicated by pictures, not words, it may beat its rival with amore in-depth version of the event. Free of time restrictions imposed on television news, a newspaper can devote as much space to a story as it sees fit, and flesh it out with more vivid details.

　　Furthermore, television by nature is a passive medium, for it deprives viewers of the freedom of selection. Whether you like or dislike a particular piece of news, all you have to do is sit in front of the tube and let it happen

　　and follow its space passively. But by reading newspapers, you can select the most interesting news, and skip what you think is irrelevant and dull; you can read in detail or briefly. Besides, watching television involves little mental activity. A constant diet of television journalism contributes to the rise in new illiteracy ,and the decline in general intellectual skills such as reading and writing. In contrast to television news, the print media encourage active involvement in what's being reported. The readers have to make greater efforts than TV viewers to follow and absorb the stories. But they acquire more in-formation and news. Reading requires high level of mental involvement, which, in turn, improves our intellectual competence. When we consider television versus print journalism on the basis of format, coverage and nature, is there any question as to which is the better source of news?