A.
B.
C.
D.无法判断
[单选题]A.B.C.D.无法判断
[单选题]A.温度变化引起的梁弯矩绝对值中部大,端部小B.温度变化引起的柱弯矩绝对值中部小,端部大C.升温时,楼板产生压应力,应力绝对值中部大,端部小D.降温时
[单选题]A.1B.CPC.脉冲信号,频率为时钟脉冲频率的1/2D.0
[单选题]A.-1.475,142.32B.-1.475,284.64C.1.475,-284.64D.1.475,-142.32
[单选题]A.-1.475,142.32B.-1.475,284.64C.1.475,-284.64D.1.475,-142.32
[单选题]A.σ≤[σ],τ<[τ]B.C.D.