题目

While we are busy living our dreams, our children are busy growing up, the people we love are moving away and dying, our bodies are getting __, and our dreams are slipping away．        A．out of date          B．out of control      C．out of shape        D．out of touch 答案：C如图所示，一根质量为m的金属棒AC用软线悬挂在磁感应强度为B的匀强磁场中，通入A→C方向的电流时，悬线张力不为零，欲使悬线张力为零，可以采用的办法是?? （??? ）A．不改变电流和磁场方向，仅适当增大电流B．只改变电流方向，并仅适当减小电流C．同时改变磁场和电流方向，仅适当增大磁感应强度D．只改变磁场方向，并仅适当减小磁感应强度