禁止在焊机上放置任何物件和（），启动电焊机前，焊钳与焊件不能（）。
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The presence of air in the condenser of a refrigeration system will （） the condensing pressure.
A. increase
B. reduce
C. maintain constant
D. None of the above is true
真空回潮机回透率的高低，不仅与真空度有关还与蒸汽和水分的压力有关。
A. 正确
B. 错误
The main objective of the SOLAS Convention is（）
A. to provide a solution of lowering pollution at sea
B. to specify minimum standards for the members composing the watch at sea
C. to specify minimum standards for ships considering their safety
D. to tell the company how to go about running their busine
期初余额调整界面有保存按钮。（）
A. 正确
B. 错误
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