与（）平行或重合的坐标轴为Z坐标。
参考答案：工件或刀具旋转轴
After Ya’an earthquake the school practiced an emergency drill showing the children how to find their “safe place”____.
A．calmly
B．regularly
C．automatically
D．specially
影响ADSL线路质量的主要因素是什么？
