题目

We have every reason to believe that __________ 2008 Beijing Olympic Games will be __________ success.   A. /; a      B. the; /      C. the; a      D. a; a 答案：C最先发现电流周围存在磁场的科学家是丹麦的    ．如图所示，通电螺线管附近的小磁针处于静止状态，则螺线管的A端是    极，电源的D端是    极．