
A.
B.
C.
D.
[单选题]A.274.6B.1000C.1663D.4274.6
[单选题]A.274.6B.1000C.1663D.4274.6
[单选题]A.30mB.35mC.40mD.45m
[单选题]A.B.10×0.45=4.5C.D.-10×0.45=-4.5
[单选题]A.3.82B.7.99C.12.56D.11.81
[单选题]A.F=300πkNB.F=3000πkNC.F=2500πkND.F=7500πkN
[单选题]A.B.10×0.45=4.5C.D.-10×0.45=-4.5
[单选题]A.-85MPaB.85MPaC.-75MPaD.75MPa