2009年4月23日，为纪念中国人民解放军海军成立60周年而举行的海上阅兵获得圆满成功，世昌号是我国目前唯一的国防员舰。若要再现民族英雄邓世昌率领中国军队抗击日本侵略者的悲壮场景，应该选择的素材是                                    

A．虎门销烟

B．丰岛海战

C．黄海海战

D．东交民巷战役

—Do you know ________ this time yesterday?

—Sorry, I don't know. [ ]

A. what she is doing

B. what was she doing

C. what she was doing