More people die of tuberculosis(结核病)than of any other disease caused by a single agent. This has probably been the case in quite a while. During the --71. early stages of the industrial revolution. Perhaps one in every seventh --72. deaths in Europe's crowded cities were caused by the disease. From --73. now on, Though, western eyes, missing the global picture, saw the trouble going --74. into decline. With occasional breaks for war, the rates of death and infection in the Europe and America dropped steadily through the 19th and --75. 20th centuries. In the 1950s,the introduction of antibiotics(抗菌素) strengthened the trend in rich countries, and the antibiotics were allowed to be imported to poor countries. Medical researchers declared victory and --76. withdrew. They are wrong. In the mid-1980s the frequency of infections and deaths --77. started to pick up again around the world. Where tuberculosis vanished, it --78. came back; in many places where it had never been away, it grew better. The --79. World Health Organization estimates that 1.7 billion people (a third of the earth's population) suffer from tuberculosis. Even when the infection rate was falling, population growth kept cases more or less constantly at 8 million a year. Around 3 million of those people --80. died, nearly all of them in poor countries.
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