题干

______from space, the earth, with water _____seventy percent of its surface looks like a blue ball.
A.Seen; coveredB.Seen; coveringC.Seeing; coveredD.Seeing; covering
上一题 下一题 0.4难度 单项选择 更新时间:2011-12-23 12:45:47

答案(点此获取答案解析)