题目锅炉水冷壁管常用的材质是 (1分)A. Q235BB. 20GC. 12Cr1MoVGD. T91锅炉水冷壁管常用的材质是 (1分)A. Q235BB. 20GC. 12Cr1MoVGD. T91题目解答答案B. 20G