单项选择题
A.10.5m,200m/s B.13.5m,225m/s C.15.0m,235m/s D.15.0m,250m/s
A.2180kN B.1970kN C.1880kN D.1730kN
A.75kPa B.100kPa C.125kPa D.150kPa