培养基连续灭菌流程中选用管道维持器,应该使培养基在管道的流速达到(),才能保证先进先出。
A.过渡流
B.层流
C.活塞流
D.湍流
参考答案:D
I was talking with my mother on the phone when we were()suddenly.
A.cut down
B.cut off
C.cut across
D.cut back
齿顶圆与齿根圆之间的径向距离称为()。
A、齿顶高
B、齿顶隙
C、齿槽宽
D、齿高