Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer for each of the blanks

The universal symbol of the Internet era communications, the @ sign used in e-mail addresses to signify the word 'at', is (23)____a 500-year-old invention of Italian merchants, a Rome academic has revealed. Giorgio Stabile, a science professor at La Sapienza University, claims to have stumbled on the earliest known example of the symbol's use, as a(n) (24)____ of a measure of weight or volume. He says the sign represents an amphora, a measure of capacity based on the terracotta jars used to transport grain and liquid in the ancient Mediterranean world.

The professor unearthed toe ancient symbol in the course of research for a visual history of the 20th century, to be published by the Treccani Encyclopedia. The first (25)____instance of its use, he says, occurred in a letter written by a Florentine merchant on May 4, 1536. He says the sign made its way along trade routes to northern Europe, where it came to represent 'at the price of’, its contemporary accountancy meaning.

Professor Stabile believes that Italian banks may possess even earlier documents (26) ____the symbol lying forgotten in their archives. The oldest example could be of great value. It could be used (27) _____ publicity purposes and to enhance the prestige of the institution that owned it, he says. The race is on between the mercantile world and the banking world to see who has the oldest documentation of @.