切削液的作用包括冷却、润滑、______和______。
参考答案:清洗 防锈
—Are these apples enough for you all?
—I'm afraid not. are need. [ ]
A. Much more
B. Many more
C. More many
供水管网经济比摩阻是()、经济流速分别是民用建筑()、生产厂房()。