_____ is even more important is that as the earth cooled down, water began to appear on its surface.

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

_____ is even more important is that as the earth cooled down, water began to appear on its surface.

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

     is even more important is              the earth cooled down, water began to appear on its surface.

______ is even more important is ______ as the earth cooled down, water began to appear on its surface.

A. What, that           B. That, what          C, That, that           D. What, what

      is even more important is              the earth cooled down, water began to appear on its surface.

A.When; that; when   B.What; whether; as   C.What; that; as     D.lt; whether; as