韶山8型电力机车轮对驱动装置大小直齿轮正确啮合的条件()。
A.模数相等
B.分度圆上压力角相等
C.齿数相等
D.模数相等及分度圆上压力角相等
参考答案:D
—What’s your teacher’s name?
—______ name is Linda.[ ]
A. She
B. Her
C. His
有了龋齿,不管疼不疼,是否都应该去找医生?