题目

Though they ________ about everything in life, Frank and Alison became good friends. A . reported B . laughed C . discussed D . disagreed 答案：D将电阻R1与R2并联后接在电源两端时，通过它们的电流之比为3：2，则它们的电阻之比为__________。若把它们串联起来接在电源两端，那么通过它们的电流之比为__________。