开关设备螺母紧固后，螺栓螺纹应露出螺母（）个螺距。
A.1
B.2
C.3
D.1
参考答案：D
Visitors to Wendeng City are usually ________ by the great number of bridges.
A．drawn
B．struck
C．pushed
D．rushed
1吨棉花比1吨糖轻一些．______．
