单项选择题
A.A3F B.16MnR C.A3 D.15MnR
A.1/10~1/20 B.1/20~1/40 C.1/40~1/60 D.1/10~1/30
A.由罐的容积 B.由罐底面积 C.由罐底直径 D.可任意
A.2~4 B.4~6 C.6~8 D.4~8
微信扫一扫,加关注免费搜题