单选题 The Intergovernmental Panel on Climate Change concluded that global warming is no game. They provide evidence that heat-trapping gases related to human activities--such as carbon dioxide from burning coal, oil, and gas--are in part driving global warming by increasing the amount of the sun's heat trapped in the earth's atmosphere. This extra heat is making the global climate system unstable. Because the climate system is complex, scientists cannot predict precisely how much and how fast the climate will change. But sophisticated computer simulations project a range of scenarios for increases in average surface temperature between 1.8° and 6.3°F (1° and 3.5℃) by the year 2100. (Bear in mind that seemingly small changes in temperature can produce major changes in climate. During the last Ice Age, global temperatures were only 5° to 9°F cooler than they are today, but that was sufficient to bury what is now Canada, New York, and New England under a kilometer of ice.)
Within the next 20 years, various regions of the world may experience severe changes in climate. Some may be vulnerable to longer droughts, others to more coastal flooding, and many to more frequent bouts of extreme weather. And if global warming continues unchecked, we could well see greater risk to human health as diseases previously found in tropical areas spread to higher latitudes and elevations. Also, insect-borne diseases such as malaria and dengue fever are already moving northward from tropical regions. Forests and wetlands provide critical benefits to human health, by filtering our air and water, and to human welfare, by providing opportunities for recreation and commerce. Changes in regional climate put many such ecosystems at risk by hindering their ability to grow and regenerate. The survival of these wetlands--often are as of high biodiversity that also provide protection against floods--depends on the water's temperature, flow, and level. Scientists are confident that global warming will reduce the area of wetlands and change their distribution. Arctic and subarctic wetlands, which are critical refuge and breeding grounds for large numbers of migratory species, are among the most vulnerable. Other coastal zone habitats--including marshes, mangroves, coral reefs and atolls, and river deltas--will also be threatened.
Avoiding these costly damages justifies immediate action to turn off the road to ruin. Scientists and economists have identified many technically feasible, cost-effective opportunities for emissions reductions, including energy-efficiency measures, advanced vehicle technologies, cuts in oil and coal subsidies, and investments in clean, renew-able energy sources like wind and solar power. To take advantage of these opportunities, governments and industry must work together. The Union of Concerned Scientists (UCS) is working to advance policies that will turn our society aside from the ruinous road to a global warming future.

单选题 By mentioning the changes of surface temperature the author means ______ .

单选题 The author mentions all of the risks listed below except ______ .

单选题 The word "advance" (Line 7, Par

单选题 It can be learned from the last paragraph that ______ .

单选题 The title of the passage would be ______ .