什么是塑件的表观质量?
参考答案:
是指塑件成型后的表面缺陷状态,如:缺料、溢料、飞边、凹陷、气孔、熔接痕、翘曲不变形等。
—Do you mind my closing the window?
—_______. It's much too noisy outside. [ ]
A. Yes, please
B. Of course not
C. All right
动物实验(animal-experiment)