before,discover,fast,in,come,watch,so,fastit,ago,shine,...
问题详情：before,discover,fast,in,come,watch,so,fastit,ago,shine,notcanLighttravelsataspeed(速度)whichisaboutamilliontimes1.________thanthatofsound. 2.________onesecond,lighttravelsabout300,000kilomete...