DP重复器的作用有（） ["拓展总线的物理长度","改变总线的拓扑结构","增加总线的接点数目","两段总线间的隔离与关断"]
购买5年期和3年期国债，其（）。 ["流动性风险相同","违约风险相同","期限风险不同","购买力风险相同"]
We came finally（）the conclusion that she has been telling lies all the time. ["of","into","to","at"]
DEH系统146模块跳线设置（）时开油动机。 ["输出为正电压","输出为负电压","输入为正电压","输入为负电压"]
进行债权投资时，应考虑的因素有（）。 ["债券的信用等级","债券的变现能力","债券的收益率","债券的到期日"]
放射源储存使用过程中的防护手段有哪些？
