熔断器是一种线路保护装置（）在电源与用电设备之间的线路使用。
A.串联
B.并联
C.混联
D.以上三种均可
参考答案：A
We haven't heard from Diana for a long time.What do you think ________ her?[ ]
A. has happened to
B. to happen to
C. has happened on
D. was happening to
在可行性研究中，不属于财务评价内容的是()。
A.项目投资现金流量预测
B.项目对国民收入贡献
C.投资方案财务评价
D.融资方案财务评价
