题目

下面电路中电流表读数如下图所示，则R1与 R2阻值之比是（        ） A、3：2          B、2：3         C、5：2          D、2：5 答案：BI know that Bob is not much of a football player , but when ________ to maths, he is among the top three in class. [　　] A．he refersB．it comes C．he leadsD．it concerns