A:突发性
B:程序性
C:无序性
D:随意性
All of us have been to the park ____________________ because both of you are ill at home.
—It's .I want to watch it again.
如图所示,在两根平行长直导线M、N中,通以同方向同大小的电流I,导线框abcd和两导线在同一平面内,线框沿着与两导线垂直的方向,自右向左在两导线间匀速运动,在移动过程中,线框中感应电流方向怎样?