阅读下面这篇短文，短文后有2项测试任务： (1) 第23-26题要求从所给的6个选项中为第2-5段每段选择1个最佳标题； (2)
第27-30题要求从所给的6个选项中选择4个正确的选项，分别完成每个句子。 Global Warming 1
Smoke is clouding our view of global warming, protecting the planet from
perhaps three quarters of the greenhouse (温室) effect. That might sound like good
news, but experts say that as the cover diminishes in coming decades, we are
facing a dramatic increase of warming that could be two or even three times as
great as official best guesses. 2 This was the dramatic
conclusion reached last week at a workshop in Dahlem, Berlin, where top
atmospheric scientists got together, including Nobel prize winner Paul Crutzen
and Swedish scientist Bert Bolin, former chairman of the UN’S Intergovernmental
Panel on Climate Change (IPCC). 3 IPCC scientists have
suspected for a decade that aerosols (浮质) of smoke and other particles from
burning rainforest, crop waste and fossil fuels are blocking sunlight and
counteracting the warming effect of carbon dioxide (二氧化物) emissions. Until now,
they reckoned that aerosols reduced greenhouse warming by perhaps a quarter,
cutting increases by 0.2℃. So the 0.6℃ of warming over the past century would
have been 0.8℃ without aerosols. 4 But the Berlin workshop
concluded that the real figure is even higher—aerosols may have reduced global
warming by as much as three-quarters, cutting increases by 1.8℃. If so, the good
news is that aerosols have prevented the world getting almost two degrees warmer
than it is now. But the bad news is that the climate system is much more
sensitive to greenhouse gases than previously guessed. 5
As those gases are expected to continue accumulating in the atmosphere
while aerosols stabilize or fall, that means "dramatic consequences for
estimates of future climate change", the scientists agreed in a draft report
from the workshop.
A. Atmospheric Scientists B. The Calculations
Made at the Berlin Workshop C. The Previous Calculations of the
Effect of Aerosols D. The Scientists’ Agreement
E. The Authoritative Conclusion F. Greenhouse Gases Paragraph 2 ______.