秦岭是我国中部重要的生态安全屏障，具有“国家绿肺”之称，也被尊称为华夏文明的龙脉，读图完成以下问题。

①调整电路后，如图（a）中电流表的示数为____安，本实验所用的电源电压为____伏，滑动变阻器的最大阻值为____欧

②根据记录的数据信息，计算出待测电阻的平均值是____欧。（精确到0.1欧）

③另一组同学在实验中，由于操作不当将滑动变阻器烧坏，若没有可替换的其他滑动变阻器，为了顺利完成实验，他们可以采取的操作方法是____。

    Surfing the Internet can help open students' eyes and get more knowledge. As a teacher, I encourage my students to use the Internet. In class those students who surf the Internet understand lessons better than the others. Besides, people can use the Internet to write letters or stories and send emails. Many students communicate with their friends online. You can also make friends by chatting on QQ. It's cheaper than calling somebody far away and it's much quicker. Nearly one third of young people surf the Internet for fun. They like to listen to music, watch films, and go to their favorite stars' websites. But can the Internet cause problems? Some of my students who used to study well at school are now failing exams. Because they spend a lot of time playing computer games.