Mathematica入门习题[9]–条件选择Which语句

第九题

y[x_] := Which[100 >= x >= 90, Return["A"], 89 >= x >= 80,
Return["B"], 79 >= x >= 70, Return["C"], 69 >= x >= 60, Return["D"],
x < 60, Return["E"], True, Return["输入错误"]]
{#, y[#]} & /@ Range[50, 120, 10]