(2007)直径为D的实心圆轴,两端受扭转力矩作用,轴内最大剪应力为τ。若轴的直径改为D/2,则轴内的最大剪应力应为:()
A.2τ
B.4τ
C.8τ
D.16τ
参考答案:C
—I'm sorry to keep you waiting so long.
—________. [ ]
A. Don't say so
B. I don't think so
C. I'd love to
D. It doesn't matter
不属于传染性海绵状脑病的是()
A.猪瘟
B.库鲁病
C.牛海绵状脑病
D.痒病
E.新型-克雅病