openings例句
        The cross - sectional areas of the pore 
openings vary along their length.
孔隙通道的 横截面 面积沿其长度方向变化.
Fine screens have 
openings of 3 / 16 inches or smaller.
细格筛的孔目为3/16英寸或更小些.
You can't afford to pass up too many 
openings like that.
你不可以像这样放弃太多的就业机会.