题目

用以下的单词写一篇短文。buy food have a picnic singdance fly a kiteplay football rain ducksswim 答案：Tomorrow is Sunday. It will be sunny and won't rain. We will have a picnic in the park. We will fly a kite and play football too. Alice and Ann can sing and dance in the park. We can see some ducks on the lake, but we can't swim in the lake. Now, we should go to buy some food for the picnic.如图所示，已知R1与R2两端所加电压为24V。如果R1=80Ω,    开关闭合后，R2中的电流为0.2A，则R2=          Ω,干路中电 流I=         A。再给R1、R2并联一个200Ω的电阻，电路中的总 电阻会变       （填“大”或“小”）。