机翼的安装角是()
A.翼弦与相对气流速度的夹角
B.翼弦与机身纵轴之间所夹的锐角
C.翼弦与水平之间所夹的锐角
D.机翼焦点线与机身轴线的夹角
参考答案:B
—What's your mother's job?
—_____.[ ]
A. She's ok
B. Fine
C. She is a nurse
D. She's well
什么是直吹式制粉系统?有哪几种类型?