【单选题】On a bowed production possibilities frontier, as you move down along the curve
A.
more of one good must be given up to receive one unit of the other good.
B.
the available production technology does not change.
C.
the opportunity cost increases.
D.
All of the above are correct.
【单选题】—Would you mind _______ your car? —No, not at all. [ ]
【单选题】--- Sit down, please! --- .
【单选题】下列关于刀具的选用说法错误的是( )。
A.
刀具的选用是金属切削加工工艺中的重要内容之一
C.
半精加工、精加工阶段以保证工件的加工精度和产品质量为主,应选用刀具寿命长、精度较低的刀具
D.
应根据工件加工区域的结构特点选择刀具切削部分的结构
【单选题】______ makes the piston to move up and down in the engine cylinder.
【多选题】关于增值税简易计税方法,说法正确的有( )。
D.
简易计税方法下的计税销售额为含增值税的销售额
【判断题】增值税的计税方法有两种:一般计税方法和简易计税方法。
【多选题】营业税改征增值税试点的增值税的计税方法包括( )。