捕收剂用量一定时,当其他药剂用量不变,只增加起泡剂用量就可以使浮选泡沫的产率增加。
参考答案：对
Which of the following statements about portfolio risk is true（）
A. In the absence of perfectly positive correlation, a portfolio will always have lower risk than the average risk of the component assets.
B. In the absence of perfectly positive correlation, a portfolio will always have lower risk than the risk of each of the component assets.
C. In the absence of perfectly negative correlation, a portfolio will always have lower risk than the risk of each of the component assets.
调度运行操作应根据调度管辖范围的划分，实行（）。
A.统一管理、分级调度
B.统一调度、分级管理
C.分级管理、分级调度
D.统一管理、统一调度
