题目

听句子，选答语。A. They're sheepB. I'm ten years old.C. His name is John.D. There are five.E. He is a teacher.⑴⑵⑶⑷⑸ 答案：【1】E【2】D【3】A【4】B【5】C如图所示的电路中，电源电压恒定不变，R1=R2．当电键S1闭合、S2断开时，电流表、电压表的示数分别为I1、U1；当电键S2闭合、S1断开时，电流表、电压表的示数为I2、U2；则I1/I2________1，U1/U2________1（选填“＜”、“=”或“＞”）．