施工成本控制应贯穿项目从（）的全过程 A.招标开始到竣工验收 B.投标开始到竣工验收 发布时间：2019-02-12 10:58 │ 来源：www.tikuol.com 题型：单项选择题 问题： 施工成本控制应贯穿项目从（）的全过程A.招标开始到竣工验收B.投标开始到竣工验收C.施工开始到竣工结算D.施工开始到竣工清算
题型：单项选择题 阅读理解。A. Control of respiration B. Basic tips for preserving cut flowers C. Role of respiration D. Most important aspect of flower care E. Need for clean water F. Ways of stopping respiration1. ( ) While everybody enjoys fresh cut flowers around his house, few people know how to keep them for aslong as possible. This may be done by keeping in mind a few simple facts. The key to keeping fresh cut flower for a week or more without preservatives ( which contain biocides (杀虫剂) that kill bacterial and fungus) is to keep the water fresh and the stems free of air pockets so they can continue to draw up water. 2. ( ) An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations retain their freshness eight times longer when kept at 12℃ than whenkept at 26℃. Keeping freshly harvested flowered at the right temperatures is probably the most important aspect of flower care. 3. ( ) The process by which flowers consume oxygen and produce carbon dioxide, called respiration (呼吸),supplies the energy the flower needs to give the flower its shape and color. The making of seeds also dependson this energy. While all living things respire, flowers have a high level of respiration. A result of all this respiration is heat, and for flowers the level of heat relative to the mass of the flower is very high. Respirationalso brings about the eventual death of the flower. Thus the greater the level of respiration, the sooner theflower dies. 4. ( ) How, then, to control the speed at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature, we know that respiration produces heat, but the reverse (反面) isalso true. Thus by keeping low temperatures, respiration is reduced and the cut flower will age more slowly.5. ( ) Another vital factor in keeping cut flowers is the quality of the water in which they are placed. Flowers find it difficult to "drink" water that is dirty or otherwise polluted. Even when water looks and smells clean, it almost certainly contains harmful substances that can endanger the flowers. To rid the water of theseunwanted substances, chlorine bleach (含氯漂白剂) can be used in small quantities. It is recommended that 15 drops of chlorine bleach be added to each liter of water. The water and solution (溶液) should also bereplaced each day. 查看答案
