Late? Or never?

摘要

Hurris is always dangerous. In 1977 smallpox was eradicated and-an accidental infection in a British laboratory a year later aside-that claim has stood the test of time. Having eliminated one viral disease, the authorities decided they ought to be able to get rid of another: polio. That, though, proved a tougher opponent. The World Health Organisation's original target, set in 1988-a polio-free world by 2000-proved illusory.