Questions 18 to 20 are based on the following passage.
At the end of the passage, you will be given 15 seconds to answer the
questions. Now listen to the passage. What do Doctor Marcia Angell and other people fear
A．To prevent the spread of HIV has a long way to go. B．The HIV-infected people in the study are not treated equally as those in industrial countries. C．The result of the study may not be effective in industrial countries. D．AIDS research is not carried out correctly in poor countries.