Not everyone has realized what_______ important part the balance of________ nature plays in their life.

A．an；the

B．/；the

C．an；/

D．the；/

在境外活动时，遇到情报机构（）时，要稳立场，巧妙处置，并及时通知我驻外使领馆。

A、策反

B、宴请

C、威胁

D、讹诈