题目

       Up to now, thousands of red phone boxes, the old image of Britain, ______ due to  mobile phones. A. removed   B. have removed       C.were removed       D. have been removed 答案：D下图中标出了磁感应强度B、电流I和其所受磁场力F的方向，正确的是[      ]      （A）                （B）              （C）                （D）