A．the Europeans were innocent in the trade of African slaves
B．slavery in Africa and in the West was the same in nature
C．the view in the most recent studies of enslavement is baseless
D．slaves had been treated even more cruelly in the African tradition

A．The necessity of the education about AIDS.
B．How to achieve the aims of AIDS courses.
C．Risks associated with AIDS.
D．Social responses to AIDS.