题干

from the moon, our earth with water seventy percent of its surface, appears a blue ball.
A.Seen; coveredB.Seen; covering
C.To see; coveringD.Seeing; covered
上一题 下一题 0.64难度 单项选择 更新时间:2015-02-05 09:49:51

答案(点此获取答案解析)