___       is well known is that Africa had contacts with India and the Red Sea civilizations from the earliest times．

1. A.
   As
2. B.
   It
3. C.
   What
4. D.
   That

___        is well known is that Africa had contacts with India and the Red Sea civilizations from the earliest times．

         A．As                       B．It                          C．What                   D．That

___        is well known is that Africa had contacts with India and the Red Sea civilizations from the earliest times．

       A．As        B．It          C．What    D．That

__        is well known is that Africa had contacts with India and the Red Sea civilizations from the earliest times．

A．As            B．It             C．What            D．That

___       is well known is that Africa had contacts with India and the Red Sea civilizations from the earliest times．