The mice ate ______ their food, They were very angry. [ ]
A. up
B. out
C. for
D. down
答案:A
早期只有局限性腹膜炎多见于()
A.脾破裂
B.肾破裂
C.十二指肠破裂
D.结肠破裂
E.胃破裂
写出比例调节器的传递函数?并画出实现P调节规律的电原理图