I didn't hear your call because I ______ to music at that time.
A:listen
B:will listen
C:am listening
D:was listening
“我军第二年作战的基本任务是:举行全国性的反攻,即以主力打到外线去,将战争引向国民党区域,在外线大量歼敌…”材料中“打到外线去”开辟大别山根据地的主力部队是( )