Unit7知识点-F部分练习 2025-2026学年沪外教版八年级英语下册

八年级英语下册Unit7知识点-F部分练习 小试牛刀 A. 选用方框中的短语填空（每个限用一次） | make ink from | hard-boiled egg | alum powder | remove the shell | hide a message | read the message | 1. The method of sharing secrets is to __________ within a __________. 2. You need vinegar and __________ to __________. 3. After boiling the egg, you __________ and __________. 4. If the message were found, it could be __________ at once. B. 句型转换（改为一般疑问句并作肯定或否定回答） 1. Giovanni Porta invented this method of hiding secret messages. 一般疑问句：________________________________________________ 肯定回答：________________ 否定回答：________________ 2. You can read the message after removing the eggshell. 一般疑问句：________________________________________________ 肯定回答：________________ 否定回答：________________ 3. The code was used for hundreds of years. 一般疑问句：________________________________________________ 肯定回答：________________ 否定回答：________________ 配套练习 A. 单项选择（★） 从A、B、C、D中选择最佳答案。 1. Who invented the method of hiding a message inside an egg? A. A French scientist. B. An Italian scientist named Giovanni Porta. C. An ancient Roman. D. A German engineer. 2. What do you need to make the invisible ink? A. Vinegar and salt. B. Vinegar and alum powder. C. Lemon juice and water. D. Sugar and milk. 3. What should you do after writing the message on the eggshell? A. Bake the egg. B. Boil the egg in hot water. C. Freeze the egg. D. Shake the egg. 4. How can you read the hidden message? A. By holding the egg under light. B. By removing the eggshell. C. By breaking the egg into a bowl. D. By eating the egg. 5. What was the weakness of this method? A. The ink was too dark. B. The message could be read at once if found. C. The egg would break easily. D. The message could only be read by the inventor. B. 完成句子（★★） 根据句子内容，用正确的词汇完成句子。 1. 这种方法的发明者是意大利科学家乔瓦尼·波尔塔。 The __________ of this method was an Italian scientist called Giovanni Porta. 2. 用醋和明矾粉制作墨水。 __________ ink from vinegar and __________ powder. 3. 用墨水在蛋壳上写下信息。 Use the ink to __________ the message on the egg __________. 4. 把鸡蛋放在热水里煮。 the egg in hot water. 5. 如果信息被发现，它可以被立即读取。 If the message were __________, it could be __________ at once. 拓展思考 介绍另一种分享秘密信息的方法 写一段话（至少5句）。说明这种方法是什么、谁发明的、需要什么材料、如何使用、有什么弱点。 使用以下表达：Another method of sharing secret information is ... It was invented by ... To use it, you need ... The steps are ... One weakness is ... __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 参考答案与解析 小试牛刀 A 1. hide a message, hard-boiled egg 2. alum powder, make ink from 3. remove the shell, read the message 4. read 小试牛刀 B 1. Did Giovanni Porta invent this method of hiding secret messages? Yes, he did. / No, he didn’t. 2. Can you read the message after removing the eggshell? Yes, I can. / No, I can’t. 3. Was the code used for hundreds of years? Yes, it was. / No, it wasn’t. 配套练习 A 1. B 2. B 3. B 4. B 5. B 配套练习 B 1. inventor 2. Make, alum 3. write, shell 4. Boil 5. found, read 拓展思考（示例） Another method of sharing secret information is the Caesar cipher. It was invented by Julius Caesar in ancient Rome. To use it, you shift each letter of the alphabet by a fixed number, for example, A becomes D. The steps are simple: choose a shift number, then replace each letter in your message with the shifted letter. One weakness is that it is easy to break if someone knows the shift number or uses frequency analysis. Today, we have much safer encryption methods. 1 学科网（北京）股份有限公司 $