高压操作冶炼特征?
参考答案:
(1)压力损失降低;
(2)边缘气流发展;
(3)煤气在炉内停留时间延长;
(4)有利于稳定顺行;
(5)除尘器瓦斯灰量减少。
毛细血管搏动征可见于()
A.二尖瓣狭窄
B.二尖瓣关闭不全
C.主动脉瓣狭窄
D.主动脉瓣关闭不全
E.三尖瓣狭窄
—How well do you know the Opera House?
—I know the place very well. I ____ Sydney many times.
A.have been in
B.have been to
C.have gone to
D.have arrived in