本站
非官方网站，信息完全免费，仅供参考，不收取任何费用，请以官网公布为准！
C
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 (暗码)are another. In a code each word is written as a secret code word or a 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 his information about the enemy before his military action. In World War Ⅱ，the Americans“broke”or figured out Japan's most important navy codes and got enough information to destroy a powerful Japanese fleet.
Storekeepers use codes to mark their goods. The codes show how much is paid for the goods or when they are 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. There 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.
28.The best title of this passage would be________.
A.Codes and ciphers B. Differences between codes and ciphers
C. History of codes and ciphers D. Inventors of codes and ciphers
29.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 1600s.
30.According to Geronimo Gardano，a trellis is ________.
A.a piece of paper with many small holes
B. a secret message with a lot of small holes
C. a letter with unreadable words and sentences
D. a sheet of paper with groups of Arabic figures
31.It is NOT mentioned in the passage that codes and ciphers are used for the purpose of ________.
A.military affairs B. commercial secrets
C. scientific achievements D. personal enjoyment
D
Some inventions are so useful, but seem so simple, that we wonder why no one thought of them long ago.
Post-it Notes were invented about twenty years ago by Art Fry, a scientist at 3M Company. The idea for the product came from an awful experience he often had while singing in his church choir. Fry used pieces of paper as bookmarks to mark the places in his book of songs, but these bookmarks were always falling out. Around that time, Fry heard about a new adhesive (粘合剂) that a colleague, Dr. Spence Silver, had created. This adhesive was special because it was strong enough to hold papers together, but not strong enough to tear the paper when it was removed.
A short time later, Fry realized that his new invention had even more uses than being a great bookmark. He came to this realization when he wrote a note on one of his new “bookmarks” and attached it to a report he was going to give to a colleague. Soon, co-workers were asking Fry for more of his invention so that they could use the new type of notes themselves.
Fry and some other people at 3M believed so much in the new product that they asked the company to give away thousands of the “sticky pieces of paper” for trial use. When some salespeople at 3M went to offices and showed workers just how helpful the new type of notes could be, they immediately received many orders. As more and more people discovered how useful Post-it Notes could be, the product took off.
32. How did Dr. Spence help Art Fry?
A. He created the Post-it Notes. B. He offered the new adhesive to Art.
C. His adhesive made Art’s invention possible. D. He often worked and discussed science with Art.
33. Which of the following is a possible use of Post-it Notes?
A. A note on a friend’s door B. An ad in a newspaper.
C. A postcard from abroad. D. An e-mail to a friend.
34. Which of the following shows the proper order of the events?
a. The company gave away many “sticky pieces of paper” for people to try.
b. Dr. Spence created a new adhesive.
c. Many orders were received and the Post-it Notes became successful.
d. Fry invented Post-it Notes.
e. His colleagues began to use the new types of notes themselves.
A. d b a e c B. b a e d c C. d e a b c D. b d e a c
35. In which column of a newspaper can we read this passage?
A. Economy B. Recreation C. Science D. Culture
英语学习 http://www.yggk.net/english/
