题目

加在某导体两端的电压为U,通过导体的电流为I,则导体的电阻为       ，若加在导体两端的电压为2U,则导体的电阻为        ，导体消耗的功率将变为原来的    倍。  答案：解析:略 ----You just think of yourself! You kept me waiting for at least three hours． ----I am sorry that you _____ think so．    A．would              B．might                  C．could           D．should