through the 19th and 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 S6. ________
declared victory and withdrew.
They are wrong. In the mid-1980s the frequency of S7. ________
infections and deaths started to pick up again around the
world. Where tuberculosis vanished, it came back; in S8. ________
many places where it had never been away, it GREw better. S9. ________
The 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 the number of clinical
cases more or less constantly at 8 million a year. Around S10. ________
3 million of those people died, nearly all of them in poor
countries.
