题目

I think Mary could be      between 20 and 30 years of age.        A. anywhere                       B. anybody                        C. anyhow                   D. anything 答案：A如图所示，当开关S闭合后，电流表A1、A2、A3的示数分别为1.2A、1A、0.6A，求：（1）通过L1、L2、的电流分别是多大？（2）一分钟内通过L3的电荷量为多少