题干
—I knocked at the door of your house at 9:00 yesterday morning . But nobody answered me.
—Oh, I ________a walk with my parents at that time .
A：take
B：was taking
C：took
D：have taken
答案(点此获取答案解析）
B
机制
，一靠民主，二靠专政，二者缺一不可
参与权、表达权、监督权