耦合是软件各模块间连接的一种度量。一组模块都访问同一数据结构应属于下列哪种耦合（）

A.内容耦合

B.公共耦合

C.外部耦合

D.控制耦合

— Do you know about the Japanese nuclear crisis(核危机)?

— Yes. I know           .

A．how are they dealing with it

B．what it has caused

C．how terrible was it

D．how long will it last