One Question per Day on Refining Knowledge (Technology) 1103011

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This post was last edited by fengdingwen on 2011-3-11 08:07. Everyone is welcome to actively participate in the learning and discussion of professional basic knowledge in the refining technology exchange area! In accordance with the forum’s unified requirements, the maximum score for this event is 5 Wealth points, and rating charm is prohibited. At the same time, friendship requests and repeated ratings are declined. Be cautious when posting; editing is ineffective. Those who have different opinions on the provided answer keys can post discussions the next day; those who provide solutions or their own opinions regarding the daily question’s answer key will receive appropriate rewards! The focus is on participation, and there are prizes for it. Please hide your replies; those that are not hidden will be deleted. Multiple-choice questions: 1. When switching from deoxygenated water to salt-free water, the pressure should be controlled at ≤（）MPA. A. 2.0 B. 2.5 C. 3.0 2. The electric shock mortality rate is highest when the power frequency is between（）hertz. A. 10～25 B. 25～50 C. 50～60 D. 60～100 3. When aromatic hydrocarbons undergo side-chain cleavage reactions, the smaller the side chain, the ( ) the cleavage. A: harder B: the same C: easier When a person is electrocuted, the fatal factor is the ( ) acting on the body. A. voltage B. current C. resistance D. inductive magnetic field 5. The liquid level in the raw material buffer tank must not be below (). A40% B20% C30% Answer key: A C A B B