How to apply   for a free mailbox  ? First you have to connect to the Internet and go to the homepage of the ICP providing free mailboxes. Then you will find an icon  , an agreement about the rules for using the free mailbox will appear. If you want to go, click the icon "I agree". Then you have to fill in a form about your basic personal data, and the name and PIN   of the mailbox. The PIN is the key to the mailbox. After finishing these, you will get a mailbox like this:your name @ mail server (for example:tvguide@mail.cctv.com.cn. "tvguide" is the name of the mailbox, and "mail.cctv.com.cn" is the name of the mail server.). The mailbox is separated   into two parts by a separator "@", which is read as "at". The former part is the name of the mailbox. The latter is the domain name   of the mail server. All mails to you will be received by the server and put into your mailbox. You can read these mails on any computer on the Internet in the world, if you have the name and PIN of the mailbox. The writer mainly wants to tell us how to    _    in this passage.
send a letter by e-mail read the e-mail on computers in the world get a free mailbox find out one's e-mail address
Question: How to apply   for a free mailbox  ? First you have to connect to the Internet and go to the homepage of the ICP providing free mailboxes. Then you will find an icon  , an agreement about the rules for using the free mailbox will appear. If you want to go, click the icon "I agree". Then you have to fill in a form about your basic personal data, and the name and PIN   of the mailbox. The PIN is the key to the mailbox. After finishing these, you will get a mailbox like this:your name @ mail server (for example:tvguide@mail.cctv.com.cn. "tvguide" is the name of the mailbox, and "mail.cctv.com.cn" is the name of the mail server.). The mailbox is separated   into two parts by a separator "@", which is read as "at". The former part is the name of the mailbox. The latter is the domain name   of the mail server. All mails to you will be received by the server and put into your mailbox. You can read these mails on any computer on the Internet in the world, if you have the name and PIN of the mailbox. The writer mainly wants to tell us how to    _    in this passage.
A. send a letter by e-mail
B. read the e-mail on computers in the world
C. get a free mailbox
D. find out one's e-mail address
Answer: