题目

I entered high school having read hundreds of books.But I was not a good reader.Merely bookish,I lacked a point of view when I read.Rather,I read in order to get a point of view.I searched books for good expressions and sayings,pieces of information,ideas,themes—anything to enrich my thought and make me feel educated.When one of my teachers suggested to his sleepy tenth-grade English class that a person could not have a “complicated(复杂的) idea” until he had read at least two thousand books,I heard the words without recognizing either its irony(嘲讽) or its very complicated truth.I某同学希望通过比较电路中不同位置的电流表的读数来研究串联电路的电流规律．所接电路图如图甲所示，闭合开关后，两电流表指针偏转情况如图乙．（1）电流表A2的读数是：0.4A0.4A．（2）该同学发现电流表A1指针偏转较A2小，所以他认为“串联电路电流每流经一个用电器，电流都会减弱一些”．请你指出造成他判断错误的原因．（3）连接电路后，两灯泡都亮，由于连线较乱，一时无法确定电路是串联还是并联，以下两种简单判断方法是否可行？请你在表中空格填写“可行”或“不可行”． 方法 操作 现象 结论 方法是否可行 方法1 把其中一灯泡从灯座中取下 另一灯熄灭 两灯一定是串联 方法2 把任意一根导线断开 两灯熄灭 两灯一定是串联