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   Everyone has worries. How do you deal with your worries? There is always something you can do to help yourself feel less worried. Sitting there worrying is no fun and it won't solve your problems.
   Grades at school are often a top worry for kids. ff you worry most about grades, ask yourself these questions:
●  Why are grades important? What do grades mean to me?
●  How do I get ready for class? Do I go over my notes even when there isn't a test?
●  Do I have a good place to do my homework?
●  Have I tried different ways of studying?
   If your worry is about a fight you had with your friend, you might write down al! the things you could do-write a note to him or her, invite him or her to watch a basketball game, say sorry to him or her and so on. Once you have a list of things you could do, you can choose one thing that could get your friend back.
   You can ask for help when you're worried. You can find someone to talk to, such as your parents, friends, and teachers.

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                                                                                                 手机定位
      ①当今时代,手机已经越来越普及,移动通信技术的发展使人和人之间的沟通更加方便,给人们的生活带来了很多的便利。手机技术的成熟和发展,同时也带动了各种新兴无线业务的出现,如彩铃、彩信和手机上网等等。我们在这里要介绍的是手机的无线定位技术。
      ②无线定位技术的应用非常广泛。在军事上,这项技术可以用以锁定敌对目标的住置。例如,在第一次车臣战争期间,俄罗斯军队用导弹击毙正在用手机通话的杜达耶夫,就使用了这项技术。在公共安全方面,警方在处理绑架案件的时候,可以通过这项技术确定使用手机的绑匪的位置。在日常生活中,这项技术可以派上大用场,倒如,给迷路的人指引方向,救助突发疾患的病人等等。
      ③无线定位可分为卫星无线定位和地面无线定位。在卫星定位技术中,最有名的就是全球定位系统(GPS),这是一种利用卫星系统实现移动目标三维定位的技术。而地面无线定位则通过测量无线电波的传播时间、信号场强、入射角度等参数实现移动目标的定位。手机定位技术属于地面无线定位系统。那么,怎么用手机来定位呢?
      ④手机发出的信号是一系列电磁波,电磁波到达基站有一定的入射角度,测量入射角度。就会得到一条从发射机到接收机的方向线,手机的位置就可以由这条方向线得到。当然了,至少要测量两个基站得到两条方向线才行。为了测量电磁波的入射角度,接收机的天线需要改进,必须配备方向性强的天线阵列。
      ⑤虽然目前的手机定位技术还存在着很多问题,但是,随着技术的发展,手机定位技术一定会更好地造福于人们。