测量轮缘厚度时，列检不掌握三轴或多轴转向架的（）轮缘厚度。
参考答案：中间轮对
司机在站正常情况下凭（）显示关门，凭推荐速度码释放后以及进路防护信号开放.
___ she was invited to the lecture made her very happy.
A．What
B．Because
C．When
D．That
