SF6设备解体检修前，应对SF6气体进行（）。根据有毒气体的含量，采取安全防护措施。
A、排放
B、冲洗
C、检验
参考答案：C
Lee devoted _________ he has to the homeless children so that they could rebuild their homes after the earthquake.
A．which
B．whatever
C．no matter what
D．that
机床坐标系的原点称为（）。
A.立体零点
B.自动零点
C.机械原点
D.工作零点
