机床几何精度检查一般是在（）状态下进行。
A、动态
B、静态
C、工作
D、空载
E、负载
参考答案：B, D
HiperLAN/2面向连接的特性有利于实现对( )的支持。
Mother told Jim to watch the milk until it boiled and then _________ off the gas. [ ]
A. turn
B. turning
C. turned
D. having turned
