题目

 在如图所示的电路中，R1、R2和R3皆为定值电阻，电源的电动势为E，内阻为r。设理想电流表A的读数为I，理想电压表V的读数为U。当R1发生断路时（     ）A．I变大，U变小，R3的功率不变          B．I变大，U变大，R3的功率增大C．I变小，U变大，R3的功率增大D．I变小，U变小，R3的功率减小  答案： B Read and answer.（阅读短文，回答问题。）Feng Yang is going to visit his grandparents this weekend. He will go there by bus. Their home is next to the Huanggang Bookstore. He is going to get off the traffic lights in front of the bookstore, then go straight. He will see their home on the right.1. What is Feng Yang going to do this weekend?____________________________2. Where is his grandparents’home?_____________________________3. How is he going to his grandparents’home?_____________________________