速度变动率越大，系统的动态稳定性越好。
参考答案：对
______ made the school proud was ____ more than 90% of the students had been admitted to the key universities.
A．What ; because
B．What ; that
C．That ; what
D．That ; because
糠壳辅料及原料皮壳中均含有多缩戊糖，在微生物作用下，生成（）。
A、乙醛
B、丙烯醛
C、缩醛
D、糠醛
