—I called you at school at half past eight last night,  but nobody answered.              

—Oh,  I _     in my office at that time.            [ ]

A. will work    

B. worked          

C. was working  

D. had worked

局内投交秘密载体的自取时间（）。

A、机要通信部门可与收件单位双方商定

B、由机要通信部门规定时间

C、自取单位应按商定的时间领取

D、接到通知后及时到机要通信部门领取