溢流阀能使其1压力保持恒定，减压阀能使其2压力保持恒定。
Why can't the man leave on Thursday?[音频]
A. Because he will have a visitor.
Because he will attend a conference.
C. Because he will have to go to New York.
D. Because he will have to stay on the farm.
What is the result of the discussion?[音频]
A. They have agreed on a rough vacation plan.
B. They have agreed on where to go on vacation.
C. They have agreed on when to go for the vacation.
D. They have agreed on when to have another discussion.
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