Question

If you and your friends wish to share a secret, you can write it in code, and no one else will be able to read it. Codes are one way of writing in secret. Ciphers (密码) are another. In a code each word is written as a secret code word or code number. In a cipher each letter is changed.

Codes and ciphers have played an important role in the history of the world. Julius Caesar, the Roman ruler who defeated almost all the countries in Europe about 2, 000 years ago, used a cipher when he sent secret messages to his troops. During the American Revolution, George Washington's spies used a kind of code to send him information about the enemy before his military action. In World War Ⅱ, the Americans "broke", or figured out, Japan's most important naval codes and got enough information to destroy a powerful Japanese fleet(舰队).

Storekeepers use codes to mark their goods. The codes show how much was paid for the goods or when they were added to the stock. Businessmen use codes to hide plans from their business enemies. Sometimes personal letters or diaries are written in code. Many people enjoy figuring out codes and ciphers simply as a hobby.

In the 16th century, codes and ciphers were very popular among scientists. They wrote messages to each other in code so that no one else would learn their secrets. Geronimo Gardano, an Italian astrologer(占星家), mathematician, and doctor, invented the trellis cipher. He took two sheets of paper and cut exactly the same holes in each one. Then he sent one sheet, which he called a trellis, to a friend and kept the other for himself. Whenever he wanted to write a message, he put his trellis over a clean sheet of paper and wrote the secret message through the holes. Then he removed the trellis and filled the rest of the paper with words that would make sense. When his friend received it, he put his trellis over the writing and read the secret message.

1. What does the underlined word "trellis"mean?

A. A piece of paper with many small holes.

B. A machine with a lot of small holes.

C. A letter with unreadable words and sentences.

D. A sheet of paper with groups of Arabic figures.

2. Which of the following statements is true?

A. Ciphers can be broken or figured out more easily than codes.

B. You could read some words in Geronimo' s letter without his trellis.

C. The first person who ever used a cipher in history was Julius Caesar.

D. Fondness of using codes was the hobby of the scientists in the 16th century.

3. The best title of this passage is________.

A. Codes and Ciphers

B. Differences between Codes and Ciphers

C. History of Codes and Ciphers

D. Inventors of Codes and Ciphers

Answer 1

1. A。最后一段第四、五句即本题答案出处。 2. B。最后一段最后两句即本题答案出处。 3. A。本篇短文主要讲的是战争年代密码的使用。