销: Ⅰ动词1.(熔化金属) melt (metal)2.(除去; 解除) cancel; annul 短语和例子注销 write off; cancel3.(销售) sell; market:产销平衡 balance between production and marketing;畅[滞] 销 sell well [poorly]; 试销 place goods on tri
垂直: perpendicular; vertical; squareness; verticality; perpendicularity 短语和例子两线垂直相交。the two lines meet at right angles. 设 ab 垂直于 cd。let ab be perpendicular to cd. 当表面与射线垂直时,射线的强度最大。when a surfa