渐开线齿轮正确啮合的条件是（）。
A.齿高相等
B.模数相等
C.压力角相等
D.齿宽相等
参考答案：B, C
根据课文内容填空
Li Hua plays football every day. In his _____小题1:_____ time, he studies English. He also enjoys _____小题2:_____ to music. It makes him _____小题3:______.
FAB分类，POX反应，非特异酯酶均阴性的是（）
A.M3b
B.AL-L3
C.M2
D.M5
E.M4E0
