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
断: Ⅰ动词1.(分成段) break; snap 短语和例子棍子断成两段。 the stick broke in two. 绳子断了。the string broke.树枝在积雪的重压下突然断了。the branch snapped under all that snow.2.(断绝;隔断) break off; cut off; stop 短语和例子断敌退路 cut off
