题目

I often go shopping with my mother on Saturday afternoons. I c___1____ the shopping bags for her. Usually we have f___2___ shopping.There is a new shopping mall near our home. It’s a l___3____ shopping mall. There are five floors of shops. We go there in the afternoon. On the f___4___ floor, we go into the shoe shop and buy my father a pair of trainers. We think t___5___ match his jeans very well. There is a b___6___ on the second floor. We buy two story books there. But when we leave the shop, we forget to p__7___ for them. Then we go up to the third floor and buy two pairs of trousers. Aft 如图交流电，通过一个电阻为R＝10.0 Ω的电阻．它在1 s内产生的热量Q＝________J，该交流电流的有效值I＝________A．(结果可以用根式表示)