数控机床的伺服系统由伺服驱动和伺服执行两个部分组成。（）
参考答案：对
Her father works as a _________ in a hotel and her mother a _________ in a private company.
A．cooker, typewriter
B．cook, typist
C．cooker, typist
D．cook, typewriter
清上焦实热宜选用
A．大黄
B．酒大黄
C．熟大黄
D．大黄炭
E．清宁片
