监测SDI所用的滤膜是()um
A.0.41
B.0.47
C.0.45
D.0.5
参考答案:C
— What's your favourite _________? — A dog.[ ]
A. food
B. drink
C. weather
D. animal
碳弧气刨时,碳棒倾角对刨槽深度影响不大。