成品片穿透率太大,如何调整?
参考答案:成品片穿透率太大,应增加溅镀厚度。
He looks very tired because he well last night.
A.didn’t sleep
B.hasn’t slept
C.slept
D.sleeps
现场阻燃处理后的木质材料,每种应取()检验其燃烧性能.
A、1m²
B、2m²
C、3m²
D、4m²