________ is known to everybody，the moon travels round the earth once every month．

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

句型转换

完成B句，使其与A句的意思相同或相近。（每空一词）

A．As is known to everybody, the moon travels round the earth once every month.

B．_____ is known to everybody _____ the moon travels round the earth once every month.