单项选择题
Passage Two Questions 30 to 32 are based on the passage you have just heard.
A.A diary. B.A fairy tale. C.A history textbook. D.A biography.
A.The first infected victim. B.A coastal village in Africa. C.The doctor who first identified it. D.A river running through the Congo.
A.Improve computer programming. B.Explain certain natural phenomena. C.Predict global population growth. D.Promote national financial health.