现场实测表明，双侧壁导坑法所引起的地表沉陷仅为短台阶法的( )。
A．1/4
B．1/3
C．1/2
D．3/4
参考答案：C
．Jack was still very calm, ______ the quarrel with the boss, and greeted every person he met on the way back to his office.
A．in spite of
B．due to
C．as a result of
D．because of
同步带传动一般不发生（）。
A、摩擦
B、变形
C、打滑
D、移动
