单项选择题
For many years marine centrifuges were designed for （） operation, that is the machines were run for a period during which solids accumulated in the bowlThe machine was stopped when the accumulated solids began to impair its performance.
A.purifying B.batch C.long period D.temporary
单项选择题 When a clarifier is running the impurities and water collect at the bowl （）.
单项选择题 A centrifuge arranged to separate impurities and small amounts of water from oil is known as （）.
单项选择题 A centrifuge arranged to separate two liquids is known as （）.
