闭环调速系统除了静态指标以外，还有（）和（）两个方面的指标。
参考答案：稳定性；快速性
— Did you go to the show last night?
— Yes, many a boy and many a girl in the area ______ invited. [ ]
A. were
B. has been
C. was
D. have been
LF炉在精炼过程中影响铝收得率的因素有（）。
A.渣中不稳定氧化物
B.钢液温度
C.钢中溶解氧
D.渣的流动性
E.渣量的多少
