无刷交流发电机实现无电刷结构的关键部件是采用了：（）.
A、交流励磁机
B、旋转整流器
C、永磁式副励磁机
D、直流励磁机
参考答案：B
亦步亦趋：主见
A．兴高采烈：恐惧
B．优柔寡断：果断
C．鼠目寸光：眼力
D．孤陋寡闻：胆识
While demanding lip service to an impractical ideal, the amateur system has left American athletes to fend themselves in a degrading world of under-the-table payoffs and over-the-table handouts.
