将呕吐分为虚实二类进行辨证论治的医家是( )
A．张机
B．张从正
C．张元素
D．张介宾
参考答案：D
Jim often has lunch at school. he eats at home today.
A．But
B．Sometimes
C．And
D．Always
什么是泵的工作点？
