题目

--I came to your house to give you the book at 2 pm yesterday, but there was no answer. --Sorry, I_________ afternoon tea. A. drank        B. was drinking        C. is drinking        D. was drunk 答案：B 在家庭电路中，半分钟内有15 C的电荷量通过用电器时，电流做了________J的功，消耗的电能为________J，通过用电器的电流是________A，用电器的电阻是________Ω．