刑法所称"战时"是指( )。

A．国家宣布进入战争状态

B．部队受领作战任务

C．部队执行戒严任务

D．遭敌突然袭击时

—Sorry, I don't know what the teacher said just now.

—He asked Maria _____.[ ]

A. how long she usually spends on her homework

B. what she was doing these days

C. why didn't Mike come to the meeting yesterday

D. when the speech will begin