矿井总风量调节，轴流式风机主要采用调节（）。
A、闸门
B、叶片安装角
C、前导器
参考答案：B
(2013·新课标Ⅱ)Only by increasing the number of doctors by 50 percent ________ properly in this hospital.
A．can be the patients treated
B．can the patients be treated
C．the patients can be treated
D．treated can be the patients
全周进汽
