中温回火后的材料具有较高的弹性极限和（）。
A、强度极限
B、屈服强度
C、耐磨性
D、红硬性
参考答案：B
— Would you mind giving your advice on how to improve our business management?
— If you make ______ most of the modern equipment, there will be ______ rise in production.
A．/; /
B．the; a
C．/; a
D．the; /
采煤工作面回采率厚煤层不小于93%
