WhatisthemainideaofPaleBlueDotbyCarlSagan?

WhatisthemainideaofPaleBlueDotbyCarlSagan?
A.Ourplanetisalonelyspeck.
B.Humanshaveimaginedself-importance.
C.Weshouldcherishourearth.
D.Therearealotofconflictsonourearth.
正确答案：C