矿井通风机性能的调节方法有哪些?
参考答案:
常用的调节方法有:1.闸门调节;2.改变通风机转速;3.改变叶片安装角;4.改变前导器角度;5.改变叶片数目。
To make the students understand the problem the teacher tried to explain it, but the explanation just did not _________to the class.
A.get through
B.get around
C.get down
D.get across
装盒中常选用分装法的是
A.少数前牙缺失B.活动矫治器C.护板D.全口义齿E.余留牙很多