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问题 单项选择题

氢－钠离子串联系统中，钠罐前设除碳器，是为了避免有二氧化碳的水通过钠罐时产生（）。

A、Na2CO3

B、NaHCO3

C、NaOH

D、NaCl

答案

参考答案：B

单项选择题

链霉素和双氢链霉素检测-酶联免疫法抗体溶液：冻干结合物用4ml稀释缓冲液重组，充分混合均匀用后9暗处2-8℃保存若长期保存，应置于（）保存。

A、2-8℃

B、室温

C、恢复至室温

D、-16—-21℃
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单项选择题

（）, which consisted of seven short blasts and one prolonged blast, all passengers have to go to their assembly station.

A.When the distress alert is sounded

B.When the emergency equipment is switching on

C.When the general emergency alarm is sounded

D.When the distress broadcast is sounded
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