单选题 The Smog(烟雾) For over a month. Indonesia was in crisis. Forest fires raged out of control as the country Suffered its worst drought for 50 years . Smoke form the fires mixed with sunlight and hot dry air to form a cloud of smog This pollution quickly spread and within days it was hanging over neighbouring countries including Malaysia．Singapore and Thailand When the smoke combined with pollution from factories and cars．it soon became poisonous(有毒的)．Dangerous amounts of CO became trapped under the smog and pollution levels rose． People wheezed f喘息)and coughed as they left the house and their eyes watered immediately． The smog made it impossible to see across streets and whole cities disappeared as grey soot(烟灰)covered everything．In some areas，water was hosed(用胶管浇)from high—rise city buildings to tIY and break up the smog．Finally，heavy rains，which came in November，put out the fires and cleared the air．But the environmental costs and health problems will remain．Many people from South-Eastern Asian cities aireadv suffer from breathing huge amounts of car exhaust fumes(汽车排放的废气)and factory pollution．Breathing problems could well increase and many non-sufferers may have difficulties for血e first time．Wildlife has suffered too．In lowland forests，elephants，deer, and tigers have been driven out of their homes by smog． But smog is not just an Asian problem．In fact，the word was first used in London in 1905 to describe the mixture of smoke and thick fog．Fog often hung over the capital．Sometimes thesmog was so thick and poisonous that people were killed by breathing problems or in accidents． About 4，000 Londoners died within five days as a result of thick smog in 1952.