题目

 Look! The children___kites over there. A. flew B. fly C. are flying D. were flying 答案：C如图所示，在匀强磁场中有一通电直导线，电流方向垂直纸面向里，则直导线受到的安培力方向是（　　）A、向左B、向里C、向下D、向外