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如图甲所示,用粗细均匀的导线制成的一只单匝圆形金属圈,现被一根绝缘丝线悬挂在竖直平面内处于静止状态,已知金属圈的质量为m=0.1kg,半径为r=0.1m,导线单位长度的阻值为ρ=0.1Ω/m,.金属圈的上半部分处在一方向垂直圈面向里的有界匀强磁场中,磁感应强度B随时间t的变化关系如图乙所示.金属圈下半部分在磁场外.已知从t=0时刻起,测得经过10s丝线刚好被拉断.重力加速度g取10m/s2.求:

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    No matter who will have difficulties at any time ,help is so necessary for everyone. The following1some advice on how to help the students who have trouble in studying.

    Help them set up the easier goal that they can achieve. The goal too high and the progress in a hurry only make us have trouble in studying. So in the daily lives and studying, they should achieve the learning goal step by step .After they make 2 progress ,they will go nearer to their last goal.

    Help them develop a good habit that is useful for 3learning .Good habits can improve grades. Before class ,they should prepare learning tools,4 markers, notebook, ruler, book etc. for the lesson. In the class ,they should listen to the teacher carefully and write down the notes. As the saying goes, “Excellence isn't 5 action, but a habit .”Good habits are the first step to success for the students who have trouble in studying.

    Help them overcome the inferiority(自卑) that is in their hearts. The students who have trouble in studying have strong inferiority more or less .So let them 6 confidence and believe their abilities. Let them believe their own strength and function .They need to tell themselves :“I can, I can study well,7 I work hard every class ,every day, every week and every term, the success will belong to me !”The person with enough 8 will be the strongest one on the earth.

    If you follow the advice above,you will help the ones who 9difficulties in studying . Without the sun, the moon isn't beautiful, either. Without the help from each other ,we also 10 warmth. Let's gives others who need help.