Today, I got up very early, I had a very good breakfast, then I went out to play with my friend. We had a very good time. In the afternoon, I went swimming with my father, it was very hot, but we felt very good in the water. After supper I
已知定值电阻R1：R2=2：3，若把它们串联在同一电路中，通过它们的电流之比I1：I2=____；若把它们并联在同一电路中，R1、R2消耗的电功率之比P1：P2=____．
“几处早莺争暖树，谁家新燕啄春泥”描述了鸟的哪种繁殖行为（ ）
