噪声门恢复时间一般可选择1ms～3s或者()。
A. 3s以上
B. 13ms～6s
C. 3ms～6s
D. 2ms～4s
During an engine room watch if immediate action is necessary to ensure safety of the ship
A. the chief engineer must be informed at first
B. the captain must be informed at first
C. it must be taken by the duty engineer
D. the generator engine must be stopped
不能通过滤菌法除去的微生物是
A. 大肠杆菌
B. 巴氏杆菌
C. 小鹅瘟病毒
D. 钩端螺旋体
E. 炭疽杆菌
用电位滴定法测果酒总酸时试样的制备：将装有样品的烧杯置于()的振荡水浴中恒温30min，取出，冷却至室温。
A. 20℃+0.1℃
B. 30℃+0.1℃
C. 40℃+0.1℃
D. 50℃+0.1℃
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