_____ milk do you need?[ ]
A. How much
B. How many
C. How often
D. How soon
A
普通滤油器滤去杂质直径d≥100um。
将固化后的涂层样板或滑片式样在溶剂中侵泡4h，然后在室温中放置（）后观察，式样涂膜不应有软化、起皱、鼓泡等现象。
