According to the text, people today think that air pollution______. A) exists merely in urban and industrial areas B) causes widespread damage in the countryside C) may have an effect on the entire earth D) is not so serious as it used to be 2. The “greenhouse effect” results from ________. A) the concentration of carbon dioxide in the air B) the blocking of sunlight C) the burning of firewood D) the increasing particulate matter in the atmosphere 3. What does the author think of the possibility of a new ice age? _____ A) He thinks that would happen soon. B) He rejects it as being ungrounded C) He holds the same view D) He is uncertain of its occurrence 4. The word “offset” (Line 3, Para4) means _________. A) slip into B) set up C) make up for D) catch up with 5. The passage is mainly about ______. A) the causes of climate change B) the possibility of a new ice age C) the effects of global warming D) the potential effect of air pollution