A study reported: using a computer at home may be bad for a child's performance in math, science and English. It can't improve them. Children are spending more time chatting   , playing games or sending and they aren't doing their homework. Li Jun, Hunan Now more and more people are buying and selling things on the Internet. Hackers around the world are interested in this. They often break in your system, but it's very difficult to find them. They even can take your money out of the bank. Xiao Yu, Guangdong I'm a 14-year-old girl in Tibet. The Qinghai-Tibet Railway was built in 2006. I can reach Beijing by train in about 48 hours. I can often go to visit my grandpa. Joma, Tibet I'm 13 years old. I want to invent a machine. My machine will _ the earthquake better and make people run to safe places. Lin Yan, Sichuan What do Hackers always do according to Xiao Yu?
They sell things on the Internet. They break in others' system to get money or other things they want. They buy things on the Internet. They protect the Internet.