转贴现买入和卖出过程要坚持（），确保安全保密。
A、前、中、后台分离
B、双人经办
C、双人临柜
D、风险可控
参考答案：B
细菌"核质以外的遗传物质"是指
A．mRNA
B．核蛋白体
C．质粒
D．异染颗粒
E．性菌毛
A 23-month-old child is brought to the emergency department with suspected croup. Which assessment finding reflects increasing respiratory distress
A．Intercostal retractions.
B．Bradycardia.
C．Decreased level of consciousness.
D．Flushed skin.
