关于酶活性国际单位定义，下列叙述哪项是正确的（） A.在特定条件下，1分钟能转化1微

如果集团内所有上下级账户之间都是实时归集的关系，便构成了（）。

A．实归资金池

B．平等资金池

C．批归资金池

D．虚拟资金池

有5种单核粒子，它们分别是₁₉⁴⁰□、₁₈⁴⁰□-、₁₉⁴⁰□+、₂₀⁴⁰□2+、₂₀⁴¹□（“□”内元素符号未写出），则它们所属元素的种类有（　　）

A．2种

B．3种

C．4种

D．5种

Which statement concerning GMDSS Radio Operator requirements is FALSE（）.

A.Each compulsory vessel must carry at least two licensed GMDSS Radio Operators at all times while at sea

B.Each compulsory vessel must carry at least two licensed Radio Operators at all times while at sea and may elect to carry a GMDSS Radio Maintainer as well

C.Communications involving safety of life at sea do not have to be logged as long as the compulsory vessel was not involved in such communications

D.While at sea，adjustments to，and the maintaining of，GMDSS equipment may be performed by the GMDSS Radio operator as long as the work is supervised by an onboard licensed GMDSS Radio Maintainer

编入货物列车中的机械冷藏车组（以下简称：机冷车组，含单节机械冷藏车），检查范围和质量标准是：空气制动机作用良好，（）规定。