当IS曲线与LM曲线的交点决定的国民收入不可能大于潜在的国民收入。
参考答案：错
28. --- Is Bob still performing?
--- I’m afraid not. He is said _____ the stage already as he has become an official.
A．to have left
B．to leave
C．to have been left
D．to be left
在直线气割4mm以下钢板时，割嘴与割件间的倾斜角度应为（）
A.前倾20°～30°
B.90°
C.后倾25°～45°
