原始误差
参考答案：
由机床，刀具，夹具，和工件组成的工艺系统的误差。
急性梗阻化脓性胆管炎(AOSC)最常见的病因是
A．先天性胆道畸形B．胆管炎性狭窄C．胰头癌D．胆管癌E．胆管结石
—Are you going to Dalian by air?
—No, the tickets are ____expensive for me.
A．very much
B．so much
C．far too
D．too much
