指示: 1.(指给人看) indicate; point out2.(指示下级) instruct 短语和例子指示某人做某事 instruct sb. to do sth.3.(指示的话或文字) directive; instructions 短语和例子发出指示 give instructions; 接到指示 receive instructions4.(显示) direction
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
