Nowadays,many people are busy in learning the knowledge of Internet. It is easy to surf the Internet, and it is more and more popular to use Internet to send e-mails. Though computers improve our life, they bring some problems. So we should use computer properly. Nowadays,many people are busy in learning the knowledge of Internet. It is easy to surf the Internet, and it is more and more popular to use Internet to send e-mails. Though computers improve our life, they bring some problems. So we should use computer properly.