双杆立好后，迈步偏差不应大于（）mm。
A.30
B.50
C.60
D.80
参考答案：A
The thief took off his shoes when he slipped into the house in order to steal something ___.
A．unnotice
B．unnoticed
C．unnoticing
D．to unnotice
进线装置没有使用合格的密封胶圈属于不完好。（）
