A.≥1.65Mpa B.≥1.9Mpa C.≥2.2Mpa D.≥2.45Mpa
A.≥100% B.≥150% C.≥200% D.≥250%
A.≥1.8Mpa B.≥2.0Mpa C.≥2.2Mpa D.≥2.4Mpa