There is ________ small temple on the island, which can only be reached by ________ water.[ ]

A. a; /

B. a; the

C. the; the

D. the; /

供配电系统设计，除一次负荷中特别重要负荷外，( )按一个电源系统检修或故障同时另一个电源又发生故障进行设计。

A．不应

B．不宜

C．必须

D．应