“机要通信寄递证”是发给与机要部门建立寄递关系的单位的（）的一种证件，作为到当地机要通信部门交寄机要文件的凭证。
参考答案：专人使用
如何建立两塔液位循环？
It was a bold idea to build a power station in the deep valley, but it______as well as we had hoped.
A．came off
B．went off
C．brought out
D．made out
