必要的;基本的 adj.要素，要点 n. e_______________
essential
暂无解析
Nothingcanstopusnow,__________?
Theresearchprojecthasonlybeenunderwayforthreemonths,soit’toosearlyto_______itssuccess.
发票;发货单n.i_______________
视力;洞察力n.v_______________
Einstein’snewtheoryonopticschanged__________scientificideaaboutlight.