He acted quickly because the man's life was ________.
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Put dirty disher in the dishwasher, or _________, the sink.
Increased production will, __________, lead to increased profits.
采用乙醇沉淀法除去水提取液中多糖蛋白质等杂质时，应使乙醇浓度达到
A. 50%以上
B. 60%以上
C. 70%以上
D. 80%以上
在醇提取浓缩液中加入水，可沉淀
A. 树胶
B. 蛋白质
C. 树脂
D. 鞣质
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