Have you ever suffered from some pains while grow up? Don't worry. I'll tell you some possible ways to deal with it. If you have few friends because you are shyly, you may try to say hello to your classmates with smile first and start to talk with them first. Then you'll find they are friendly but very easy to get along with. To get good grades, you had to stop reading entertainment magazine, and try your best to learn your lessons well. Believe on yourself, and you'll be successful. If you have any questions, and you can turn to your friends or teachers for help.
＝1×106C／kg，且速度方向与磁场方向垂直。若各离子间的相互作用和离子的重力都可以忽略不计。