Question

【题目】

Scientists have discovered a new kind of invisible ink. It’s called water. And all you need for this secret-messaging ink to work is to write with it on a super-hi-tech piece of paper coated with special chemicals. 【1】 It shows up darker than the surrounding paper under UV(紫外线的) light.

When the message has been read and needs to be hidden again, get out your hairdryer, and blow some warm air on the paper. 【2】

Using hot air from a hairdryer for 15-30 seconds, you were able to reuse the special paper up to 30 times because the heat reorganized the chemical structure of the paper coating. 【3】

The invention was made by a group of scientists in China, led by Qiang Zhao of the Institute of Advanced Materials, Nanjing University of Posts and Telecommunications.

Although much of modern communication is digital(数码的), there are still some situations in which it is important to send messages on a piece of paper, such as when the people don’t have Internet. 【4】 But the problem has always been how to get rid of a message once it has been shown so no one else can read it.

【5】. To use it, write with the lemon juice on ordinary paper, iron(熨) the paper with a hot iron and the hidden message will appear. The downside(缺点) is that the paper has to be destroyed to hide the message so no one else can read it.

A.How to make the invisible ink? Follow the steps.

B.Invisible inks have long been used to send secret messages.

C.Without the heat, the message stayed visible for up to three months.

D.Previously, the most readily available invisible ink was lemon juice.

E.Shine a UV light on the coated paper and the water message becomes visible.

F.Then the message will be gone and the paper can be reused, which keeps costs low.

G.Putting water on the paper broke up the structure of the chemicals it was coated with.

Answer 1

【答案】

【1】E

【2】F

【3】C

【4】B

【5】D

【解析】

这是一篇说明文。文章介绍了隐形墨水的使用方法，优缺点等。

【1】

根据第一段的内容可知，该段介绍的是隐形墨水的使用原理，上一句提到“要让这种传递秘密信息的墨水发挥作用，你只需要在涂有特殊化学物质的超级高科技纸上写字。”承接上文，E选项“用紫外光照射涂后的纸，水的信息变得清晰可见。”切题。下文“在紫外线下，它比周围的纸颜色更深。”对E选项做了解释说明。且该选项中的UV light，coated paper与前后文相对应。故选E项。

【2】

第二段讲述了当信息读完需要再次隐藏时的做法，上一句提到“拿出你的吹风机，吹一些热风在纸上”承接上文，F选项“然后，信息就会消失，纸张就可以重复使用，这就降低了成本。”切题。该选项中“the message will be gone” 信息就会消失和上文呼应。故选F项。

【3】

第三段介绍了隐形墨水的重复使用的有关事项，上一句提到“用吹风机吹15-30秒的热风，你可以重复使用这种特殊的纸多达30次，因为热量重组了纸涂层的化学结构。”，是经过加热后的纸张的的使用情况，承接上文，C选项“在没有加热的情况下，这条信息可以持续3个月。”切题。故选C项。

【4】

前句提出，人们在一些情况下不得不使用纸张来传递信息。B选项“长期以来，隐形墨水一直被用来发送秘密信息。”是前句的结果，正因为不得不使用纸张，隐形墨水才会得到长期的应用。下文“但问题一直是，一旦消息显示出来，如何删除它，这样其他人就无法阅读它。”是人们长期使用墨水所遇到的问题。在此处，B选项能够起到承上启下的作用。使语义通顺。故选B项。

【5】

根据下文“用柠檬汁在普通纸上书写来使用它，用热铁熨，隐藏的信息就会出现。”可知，该段介绍了柠檬汁作为隐形墨水的使用方法。D选项“在此之前，最常见的隐形墨水是柠檬汁。”切题。且该选项中的 lemon juice与后文相对应。故选D项。

七选五的解题技巧之一是根据上下文词汇来锁定线索。即：要关注空白前后的名词和动词，然后在选项中查找它们的近义词、反义词、同义词、同类词等。其次是一些专有名词，比如说数词、代词、时间、年代、地点/名称等。在本文中，第1小题中的“UV light，coated pape”，第2小题中的“he message will be gone”，第5小题中的“ lemon juice”均与上下文有相呼应的词语。