专题10 2016年高考英语全国I卷七选五、短文填空、短文改错素材核心词汇语境剖析与练习-备战2019年高考英语最新五年真题中的核心词汇语境剖析与练习

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。 Secret codes(密码)keep messages private. Banks, companies, and government agencies use secret codes in doing business, especially when information is sent by computer. People have used secret codes for thousands of years.　36　Code breaking never lags(落后)far behind code making. The science of creating and reading coded messages is called cryptography.  There are three main types of cryptography.　37　For example, the first letters of “My elephant eats too many eels” spell out the hidden message “Meet me.”  　38　You might represent each letter with a number, for example. Let’s number the letters of the alphabet, in order, from 1 to 26. If we substitute a number for each letter, the message “Meet me” would read“13 5 5 20 13 5.”  A code uses symbols to replace words, phrases, or sentences. To read the message of a real code, you must have a code book.　39　For example, “bridge” might stand for “meet” and “out” might stand for “me”. The message “Bridge out” would actually mean “Meet me.”　40　However, it is also hard to keep a code book secret for long. So codes must be changed frequently.  A. It is very hard to break a code without the code book. B. In any language, some letters are used more than others. C. Only people who know the keyword can read the message. D. As long as there have been codes, people have tried to break them. E. You can hide a message by having the first letters of each word spell it out. F. With a code book, you might write down words that would stand for other words. G. Another way to hide a message is to use symbols to stand for specific letters of the alphabet. ★语篇解读★ 【关键词】Secret codes(密码); Code breaking 【主旨概要】本篇主要论述了密码的设置以及对密码的解法。 ★语言知识★ 【核心词汇】 1. Code breaking never lags far behind code making. 2. 密码的破译永远不会被密码的编造甩在后面 3. spell out the hidden message拼出每个词的第一个字母去隐藏信息 4. you must have a code book使用密码本 5. private a. 私下的 6. message n. 信息 7. substitute v. 代替 8. Code代码 9. agency代理/机构 10. as long.as=if只要 11. symbol