Read the passage and choose correct word or phrase that best fits each of the numbered blanks.
(26) ______________ groups are putting pressure on governments to take action to reduce the amount of carbon dioxide which is given (27) _____________by factories and power plants, thus attacking the problem at its source. They are in favor of more money being spent on research into solar, wind and wave energy devices, (28) _____________ could then replace existing power station.
Some scientists, (29) _____________, believe that even if we stopped (30) __________ carbon dioxide and other gases into the atmosphere tomorrow, we would have to wait several hundred years to notice the (31) __________. Global warming, it seems, is to stay.