Part Ⅱ Reading Comprehension (Skimming and Scanning)
Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, choose the best answer from the four choices marked A), B), C) and D). For questions g-10, complete the sentences with the information given in the passage.
Happy Earth Day
The Good News
Here's the good news: our air is cleaner, our lakes are purer, our forests are healthier, endangered species are recovering, toxic emissions are down, and acid rain has diminished dramatically. And yet, if you've looked at a newspaper or watched the evening news lately, you might think our environment is under siege (围攻). Media Coverage of the environment is heavy on doomsday, but the truth is not at all bleak: nearly all environmental trends in the United States are positive and have been for years—if not decades.
Eco-legislation, green organizations, corporate cooperation and new inventions have all quietly steered our environment in a positive direction. We can't afford to be complacent (自满的), though—especially when it comes to greenhouse gases, since global warming is the one huge problem we haven't really tackled. But almost every measure taken by government agencies and grass-roots efforts to improve the environment has shown encouraging results—usually faster than expected end at a lower cost. Now that's good news.
Scientists and environmentalists think that even the worrisome fact of global Warming can be ameliorated (改善). There is a strong scientific consensus that the global warming threat requires action, but if current environmental trends persist and the reduction of most pollutants continues to be accomplished faster and more cheaply than expected, we may be able to control and reduce greenhouse gases in both affordable and practical ways.
Consider some of the environmental improvements the United States has witnessed over the last three decades.
Improved Air Quality
Take a nice, big cleansing breath. According to the Environmental Protection Agency, emissions of. the primary smog-causing chemicals from cars and trucks have declined 54 percent since 1970, even though the number of registered cars and trucks has more than doubled, from 108,407,000 to 230,428,000, and they are now driven one and a half times as far annually.
Keep breathing, because the fine particulates linked to respiratory disease, including those sometimes seen as soot(煤烟), are down by about one-third since 1979 (though fewer cities were surveyed back then). The level of carbon monoxide, a dangerous odorless gas, is down 53 percent since 1970. And emissions of sulfur dioxide, often the major culprit behind acid rain, are down 49 percent since 1970, despite the fact that the United States now bums far more coal, the main source of this pollutant.
These improvements have translated into better air quality for millions of Americans. Between 1976 and 1990, the Los Angeles area averaged some 150 days per year in violation of federal smog standards; in 2004, that figure dropped to just 27 violation days, the fewest ever for that city.
And, in case you are wondering, federal standards have become stricter, not weaker, during this period. Of course, there is more to be done—27 smog days in Los Angeles are still 27 too many, and Atlanta, Houston and other cities continue to experience air-pollution problems. But overall, air-quality trends are strongly positive. Now, exhale.
Better Water Quality
Other environmental trends are equally encouraging. Water quality has improved, too, and rates of waterborne disease are also in decline. It's hard to believe, but just a generation ago, factories and municipal plants actually disch

A. Global warming.
B. Acid rni9.
C. Toxic emission.
D. Environment.