Which protocol is used to upload files to and download files from a remote server on the internet?

The correct answer is B, Trash. When a letter is deleted from a mailbox it is not wiped out at once. It is moved to a folder called Trash, or Bin in some services, and kept there for a fixed number of days so that a letter deleted by mistake can be restored. Only when the folder is emptied, or the holding period ends, is the letter removed for good.

Option A, Drafts, holds letters that have been written but not yet sent, so a deleted letter never lands there. Option C, Inbox, is the folder where arriving mail is kept, and deleting a letter is precisely the act of taking it out of the Inbox. Option D, Sent mail, keeps copies of the letters you have already despatched, which is a record of outgoing post and not of deleted post. Trash is therefore the only correct choice.

The correct answer is B, To. The To field of a mail window is meant for the addresses of the people the letter is written to. More than one address can be typed there, separated by commas, and every recipient can see the whole list. Copies can also be sent through the Cc field, which all recipients see, or the Bcc field, which no other recipient sees.

Option A, Subject, is the one-line heading that tells the reader what the letter is about, and an address typed there would never be treated as a destination. Option C, Message, is the body of the letter, where the matter is written. Option D, From, shows the sender's own address and is filled in automatically by the mail service, so it names the writer and not the reader. Hence only the To field carries the recipients' addresses.

The correct answer is B, 1969. ARPANET was funded by the Advanced Research Projects Agency of the United States Department of Defense, and in 1969 it linked computers at four American universities and passed its first message between them. That experiment proved that packets could be switched between distant machines and grew into the internet.

Option A, 1959, is too early: the packet-switching idea had not yet been worked out and no such network existed. Option C, 1979, falls well after ARPANET was working and is remembered instead for early newsgroups. Option D, 1989, is the year Tim Berners-Lee proposed the World Wide Web at CERN, which is a service on the internet and not the network itself; papers often place 1989 as a distractor for exactly this reason. Remember the pair 1969 for ARPANET and 1989 for the Web.

The correct answer is C, Tim Berners-Lee. Working at CERN in Switzerland, he proposed a system of linked documents in 1989, wrote the first browser and server, and put the first website online in 1991. HTML, HTTP and the URL all come from his design, which is why he is called the inventor of the World Wide Web.

Option A, Vinton Cerf, designed the TCP/IP protocol suite along with Robert Kahn and is called a father of the internet, which is the network rather than the web. Option B, Charles Babbage, belongs to the nineteenth century and is the father of the computer for his Difference and Analytical Engines. Option D, Ray Tomlinson, sent the first network email in 1971 and chose the @ sign for addresses. Each of the three is famous, but only Berners-Lee is tied to the Web.

The correct answer is C, the @ sign. Ray Tomlinson sent the first message between two computers on ARPANET in 1971 and needed a character that would never appear in a person's name. He picked @, which already meant at in trade bills, so that an address could be read as a user at a place. Every email address since then has the form user@domain.

Option A, the hash, is used to mark tags on social sites and as a comment sign in some programs, never as the divider in a mail address. Option B, the ampersand, means and and is used in program names and file paths. Option D, the asterisk, works as a wild card in searches and as the multiplication sign in spreadsheets and programming. Only @ separates the two halves of an email address.