A. has been put into actual use B. was put into actual use in 1977 C. was put on experiment in 1977 D. had been repeatedly experimented on before 1977 参考答案:C 答案解析:[分析] 第三段第一句……,the new system was used successfully in an experiment in Chicago in 1977.答案选C。
第4题: [多项选择]回购协议市场的交易特点有( )。 A. 流动性强 B. 安全性高 C. 收益稳定 D. 税收优惠 E. 交易对象为金融债 参考答案:A,B,C 答案解析:[解析] 回购协议市场的交易特点如下:①流动性强;②安全性高;③收益稳定且超过银行存款收益。对于商业银行来说,利用回购协议融入的资金不属于存款负债,不用交纳存款准备金。