A.
B.
C.
D.
[单选题]A.320kNB.340kNC.360kND.380kN
[单选题]A.B.C.D.
[单选题]A.0B.C.πD.
[单选题]A.1.5kN·mB.2kN·mC.2.5kN·mD.0kN·m
[单选题]A.条件(1)充分,但条件(2)不充分B.条件(2)充分,但条件(1)不充分C.条件(1)和条件(2)单独都不充分,但条件(1)和条件(2)联合起来充