Thanks to the efforts of intrepid voyagers in the last three centuries -- actually, we know also thanks to satellite technology, of course -- we know almost every single square meter of our planet's surface.
多亏三个世纪以来英勇无畏的探险家们—— 当然，也少不了卫星技术的帮助—— 我们几乎对地球表面的 每一寸土地都了如指掌。