题目

通电螺线管周围的磁感线分布与________相似，它两端的磁极与________有关，可以用________判断通电螺线管的极性跟电流方向的关系． 答案：【答案】 条形磁铁 电流方向 右手螺旋定则【解析】由课本实验知，通电螺线管的周围小磁针的排布情况与条形磁铁的排布情况一致，所以可以确定其周围的磁场与条形磁铁的磁场一致；通电螺线管周围的磁场方向跟电流方向有关，改变电流方向则磁极的极性也发生变化；判断通电螺线管的极性跟电流Ⅰ栏是5个人的不同情况，Ⅱ栏中是7种不同的建议，请将它们配对。其中有两项是多余的。(   ) 1. It takes me much time to remember the new words，but I nearly forget all of them after a few days.(   ) 2. I’m bad at reading English articles，because there are too many new words in them.(   )3. I can’t write down the words when I am listening，although I can hear every word clearly.(   )4. I’m good at English, but I’m afraid to speak English with others.(   )5. I can understand my English teacher in class, but I always find that it is hard for me to finish the exercises by myself.A. Try to review (复习) the things that you learn in a day. Ask your teachers or your classmates more about your questions.B. Don’t stop to think when you hear the new words. You don’t need to know every word in the articles.C. You don’t need to know each word when you are reading. Sometimes you can guess the meeting of the mew words, and then you can get the main (主要的) ideas.D. you should do more exercises and try to write down all the words you hear. I think you will make progress (取得进步).E. Review the words again and again until you remember them.F. Don’t spend all your time on study. Try to relax yourself.G. Don’t worry. Try to speak English more with your good friends first. When you can do it well, speak to others.