主动脉弓下方毗邻不包括（）。
A.左喉返神经
B.肺动脉
C.动脉韧带
D.左主支气管
E.心深丛
参考答案：E
Inventor旋转零件视图快捷键是（）。
A.F4
B.Shift
C.Alt+Shift
D.Shift+鼠标滚轮
The symbols of mathematics which we are most familiar are the signs of addition, subtraction, multiplication, division and equality.
