一天,我弹完电子琴和妈妈聊天。妈妈问我:“儿子,你知道电子琴有几个琴键吗?”我说:“那我可不知道,还是让我数数吧。”妈妈鼓励我说:“你动动脑筋想一想,不数也可以知道答案的。”“真的吗?”我简直不敢相信,我马上静下心来,仔细观察起电子琴琴键的特点。我发现:原来电子琴琴键的排列是有规律的,其中就有比较完整的七组音阶,每组音阶有7个白键,5个黑键。先 One day, I finished playing the keyboard and chatting with my mom. Mom asked me: “Son, do you know the keyboard has a few keys?” “I said: ” Then I do not know, let me count it. “Mom encouraged me to say: ” A few, you can know the answer. “” Really? "I could not believe it, I immediately stop and carefully observe the characteristics of the keyboard piano. I found that: the original arrangement of the keyboard keys are regular, of which there are more complete seven groups of scales, each group has seven white keys, five black keys. first