from space, the earth , with water seventy percent of the surface , looks like a blue ball.
A. Seen ; covered
B. Seen ; covering
C. seeing ; covering
D. Seeing ; covering
网友回答
A. Seen ; covered
(答案→)B. Seen ; covering
C. seeing ; covering
D. Seeing ; covering
解析：可联系答.案.网客服索取。