何谓色谱固定液、固定相、载体、柱填料？ It is customary in shipping practice to quote freight rates（）weight or measurement,ship’s option. ["on the basis of","as a result of","arise from","come into being"] 什么是恩氏粘度？ （）is not ordinarily applied to passenger or to combination passenger and freight ships. ["displacement tonnage","deadweight tonnage","registered tonnage","gross tonnage"] 油品的实分子平均沸点指什么？ 石油产品的灰分从哪里来？