实验室有一瓶久置的氢氧化钙粉末，某学习小组对这瓶氢氧化钙粉末的成分进行操究。 [提出问题l这瓶氢氧化钙粉末是否变质?
[猜想一]小丽同学认为这瓶氢氧化钙粉末已经变质。
[实验验证]请你设计实验证明小丽同学的观点，简要写出实验步骤及现象： 。
[结论一]这瓶氢氧化钙粉末已经变质。
[猜想二]小明同学认为“结论一”不全面，这瓶氢氧化钙粉末可能部分变质。
[实验验证]小明同学设计实验进行验证，请你将他的实验报告补充完整。
| 实验步骤 | 实验现象 | 实验结论 |
| 这瓶氢氧化钙粉末部分变质 |
[思维拓展]由以上实验可知，清洗盛放石灰水的试剂瓶壁上的白色固体时可用 ，请写出有关反应的化学方程式 。
取少量粉末于试管中，向试管中加入适量的稀盐酸，有气泡产生
稀盐酸；CaCO3+2HCl==CaCl2+H2O+CO2↑
Passage One
| Researchers said it was clear that the world’s oceans play a major role in queuing up rapid climate changes, but that thus far the mechanics (机制，结构) of such changes were poorly under stood. "It’s like being blindfolded and walking toward the edge of a cliff," said Wallace Brocker, a professor of environmental sciences at Columbia University. "We don’t understand (the factors) so we don’t really know what to look for." Using ice cores drilled from glaciers and other ice sheets, the researchers have developed a model showing world temperatures’ rising and falling with unsettling frequency over the past110 000 years. While some of the changes have been slow and steady, such as the end of the last Ice Age some 12 000 years ago, others have been swift and unexpected, such as the rapid warming of the North Atlantic from 1920 to 1930 and the Dust Bowl drought of the 1930s. The most drastic temperature changes—believed to be as much as 18 degrees Fahrenheit over the space of just a few years—exceed any recorded in human history, they said．This was not in tended to alarm the public, but that they hoped it would stimulate policy makers to prepare for the possibility of rapid temperature flux. Greenhouse gases, emitted by fossil fuels such as oil and coal, have been linked by many re searchers to a rise in global temperatures. A 1997 Kyoto Treaty on global warming sought to cut emissions of such gasses by developed nations, but the Bush administration this year spurned (轻蔑或傲慢地拒绝) the treaty, saying pollution controls would be too costly for the U.S. economy. The NAS panel called for research to identify what it described as "no-regrets" measures that would cost relatively little and would be good policies regardless of the extent of environmental change. Such measures could include regulations to reduce damage to water, air and land, or slow climate change, or helping societies cope with abrupt climate changes by developing new financial instruments such as weather derivatives (衍生证券) and catastrophe bonds to reflect the risks. Societies have faced both gradual and abrupt climate changes for millennial and have learned to adapt through various mechanisms, such as moving indoors, developing irrigation for crops, and migrating away from inhospitable (不适宜居住的) regions. It is important not to be fatalistic (宿命论的) about the threats posed by abrupt climate changes. |
According to the passage, developing new financial instruments such as weather derivatives could______.
A．help societies cope with abrupt climate changes
B．reflect the risks of abrupt climate changes
C．help prevent slow climate changes
D．Both A and B