if(X>=90，"a",if(X>=80，"b",if(X>=70，"c","")))
比如A1是数值，另一单元格公式 =IF( OR(A1<70,A1>100),"超过范围",CHOOSE((A1-60)/10,"a","b","c"))
=if(and(a1>=70,a1<80),"c",if(and(a1>=80,a1<90),"b",if(and(a1>=90,a1<100),"a","数据溢出")))
