Questions 47 to 51 are based on the following passage.
Even in this electronic era. paper continues to play a complete role in our daily lives. Americans depend on about 85 million tons of paper and paperboard a year to help us clean, organize, advertise, educate and much more, according to the Environmental Protection Agency.
Unfortunately, this soft product comes with environmental disadvantages. These include the loss of biological variety associated with permanent forest, an energy and water intensive production process that generates greenhouse gases and other erous products, and a life cycle that ends in a landfill (垃圾掩埋法) or incinerator (焚烧炉) nearly half the time.
Of course, we have choices. We can lessen paper’s environmental blow first and foremost by reducing our dependence (using cloth towels in the kitchen, printing on both sides of the sheet at the office, etc. ). And, when we really need to use paper, we can make better-educated buying decisions.
Here are a few tips for purchasing eco-friendly paper:
Buy recycled, Doing so saves landfill space, supports green jobs and "reduces the total amount of resources you’re using," says Susan Kinsella, executive director of Conservatree, an organization that advocates using more paper which can be used again.
Study labeling carefully. Look for products that contain post-consumer waste (or material that ham completed a full life cycle); the higher the percentage, the better. A chasing-arrows symbol may simply mean a paper product can be recycled, while the word "recycled" may refer to only a small percentage of recovered fibers.
Demand certificate. A number of organizations certify that the original fiber used in a given paper comes from responsibly managed forests. Kinsella says the one environmentalists trust most is the Forest Stewardship Council. Check with your printer or paper supplier to see whether it carries FSC-certified lines.
Consider tree-free options. Some paper is now made from agricultural crops, several of which have a higher yield per acre than some types of trees used in paper and may have other benefits. Tree-free material is available for personal use (think cards and invites), but before buying, investigate its origins and the farming practices used. For a list of suppliers, check out http://www. conservatree.org//treefree.html.
Check color. Paper which is made whiter without the use of Cl₂ (氯)or other chemicals is less polluting. Using paper without Cl₂ is another step up. And when using a professional printer, ask for vegetable-based inks.
We may save some types of trees used in paper by ______.