A.1.18~1.47MPa B.1.96~3.96MPa C.5.58~9.80MPa D.11.77~13.73MPa
A.小于 B.大于 C.等于
A.0.1~0.15% B.0.15~0.18% C.0.2~0.1% D.0.1~0.05%