______ is known to all, the earth travels round the sun once every year．

______ is known to all, the earth travels round the sun once every year．

　 A．That　 B．As　 　 C．What　 D．It

______ is known to all, the earth travels round the sun once every year．

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

34. _________ is known to all is that the earth goes round the sun.

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

 _________ is known to all, the moon travels round the earth once every month.

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