拧紧的过程是通过扭矩，利用螺栓的（），实现夹紧力。
A.摩擦力；
B.张紧力；
C.剪切力；
D.压力
参考答案：B
He is quite strange, for everything he does is opposite to _____ is considered normal behavior.[ ]
A. whether
B. that
C. what
D. which
简述煤堆的降温措施。
