单项选择题 While Jane was cooking fish on openfire outside，her hair caught． fire． A．不填；a B．不填；不填 C．an；a D．an；不填

单项选择题 One of the sides of the board should be painted yellow，and ． A．theother is white B．anotherwhite C．theother white D．another is white

未知题型 有一螺母M24×2—6H，加工后，测得中径为D2a=22．785mm，△P∑=0．030mm，△α／2(左)=+35，△α／2(右)=+25， (1)试计算螺母的作用中径，判断中径是否合格； (2)画出中径公差带图。