📚 Year 7 WJEC Computer Science: Mock Exam Paper Walkthrough | 七年级WJEC计算机：单元测试模拟卷解析
This walkthrough takes you through a typical Year 7 WJEC Computer Science unit test. Each question is explained step by step to help you understand key concepts and avoid common mistakes. Use this guide to consolidate your knowledge and build confidence before the real assessment.
本解析将带你逐题回顾一份典型的七年级WJEC计算机单元测试卷。每道题都逐步讲解，帮助你理解核心概念并避开常见错误。请使用本指南巩固知识，在正式测评前建立信心。
1. Identifying Hardware and Software | 硬件与软件辨识
Question: Classify each of the following as either hardware or software: monitor, web browser, printer, operating system, keyboard, spreadsheet application.
题目：将下列各项归类为硬件或软件：显示器、网页浏览器、打印机、操作系统、键盘、电子表格应用程序。
Hardware refers to the physical components of a computer system that you can touch. Software is a set of instructions that tells the hardware what to do. A monitor, printer, and keyboard are physical devices, so they are hardware. A web browser, operating system, and spreadsheet application are programs or sets of instructions, so they are software. Always remember: if you can kick it, it is hardware; if you can install it, it is software.
硬件指计算机系统中可以触摸到的物理部件。软件是指挥硬件工作的指令集。显示器、打印机和键盘是物理设备，因此属于硬件。网页浏览器、操作系统和电子表格应用程序是程序或指令集，因此属于软件。始终记住：能踢到的是硬件，能安装的是软件。
2. Input and Output Devices | 输入与输出设备
Question: State whether each device is an input device, an output device, or both: touchscreen, speakers, microphone, projector, barcode scanner, headphones.
题目：判断以下设备是输入设备、输出设备，还是两者兼具：触摸屏、音箱、麦克风、投影仪、条形码扫描器、耳机。
Input devices send data into the computer. Output devices receive data from the computer. A touchscreen is both because it displays output and accepts touch input. Speakers and headphones are output devices (sound comes out). A projector is an output device. A microphone is an input device. A barcode scanner is an input device. Knowing the direction of data flow helps you decide.
输入设备将数据送入计算机。输出设备从计算机接收数据。触摸屏既是输入也是输出，因为它显示输出并接受触摸输入。音箱和耳机是输出设备（声音传出）。投影仪是输出设备。麦克风是输入设备。条形码扫描器是输入设备。了解数据流的方向有助于你判断。
3. Binary Representation | 二进制表示
Question: Convert the denary number 29 into an 8-bit binary number. Show your working.
题目：将十进制数29转换为8位二进制数，并写出过程。
To convert, write down the place values for 8 bits: 128, 64, 32, 16, 8, 4, 2, 1. Then see which values sum to 29. Start with the largest. 16 fits (29 – 16 = 13). 8 fits (13 – 8 = 5). 4 fits (5 – 4 = 1). 1 fits (1 – 1 = 0). So we put 1s under 16, 8, 4, and 1. All other places are 0. The result is 00011101. In 8-bit form we write all eight digits: 00011101₂.
转换时，先写出8位的位权值：128、64、32、16、8、4、2、1。然后找出哪些值之和等于29。从最大的开始。16合适（29-16=13）。8合适（13-8=5）。4合适（5-4=1）。1合适（1-1=0）。因此在16、8、4、1下方写1，其余位写0。结果是00011101。8位形式为00011101₂。
4. Data Storage Units | 数据存储单位
Question: Put the following units in order from smallest to largest: gigabyte, byte, megabyte, kilobyte, terabyte. How many bytes are there in one megabyte?
题目：将以下单位按从小到大的顺序排列：千兆字节、字节、兆字节、千字节、太字节。一兆字节等于多少字节？
The correct order is: byte, kilobyte, megabyte, gigabyte, terabyte. A byte is the smallest unit listed. One kilobyte is 1024 bytes. One megabyte is 1024 kilobytes, so 1 MB = 1024 × 1024 = 1 048 576 bytes. Remember that computer storage uses binary-based multiples, not powers of 1000.
正确顺序是：字节、千字节、兆字节、千兆字节、太字节。字节是列出的最小单位。1千字节=1024字节。1兆字节=1024千字节，因此1 MB = 1024×1024 = 1 048 576字节。记住计算机存储使用基于二进制的倍数，而非1000的幂次。
5. Algorithms and Flowchart Symbols | 算法与流程图符号
Question: Match each flowchart symbol to its meaning: oval, rectangle, diamond, parallelogram, arrow.
题目：将以下流程图符号与其含义配对：椭圆形、矩形、菱形、平行四边形、箭头。
In flowcharts, the oval represents start or end. The rectangle is a process or instruction. The diamond is a decision (yes/no). The parallelogram is input or output. Arrows show the direction of flow. Being able to read and draw these symbols helps you design clear algorithms.
在流程图中，椭圆形表示开始或结束。矩形表示处理或指令。菱形表示判断（是/否）。平行四边形表示输入或输出。箭头表示流程方向。能够读懂并绘制这些符号有助于设计清晰的算法。
6. Sequence, Selection, and Iteration | 顺序、选择与迭代
Question: A program asks for a password. If the password is correct, it says ‘Access granted’ and ends. If incorrect, it asks again. Identify the programming constructs used.
题目：一个程序要求输入密码。如果密码正确，显示“访问授权”并结束；如果错误，则再次询问。请指出使用了哪些编程结构。
The program executes steps in order (sequence). It checks a condition – whether the password is correct – this is selection. Because it may repeat the asking step until the correct password is entered, that is iteration (a loop). All three basic constructs are present: sequence, selection, and iteration.
该程序按顺序执行步骤（顺序）。它检查条件——密码是否正确——这是选择。因为可能重复询问直到输入正确密码，这是迭代（循环）。三种基本结构全部出现：顺序、选择和迭代。
7. Interpreting Pseudocode | 伪代码解读
Question: Study the following pseudocode and predict the output.
SET total TO 0
FOR count FROM 1 TO 5
SET total TO total + count
END FOR
OUTPUT total
题目：阅读以下伪代码并预测输出。
将total设为0
FOR count从1到5
将total设为 total + count
END FOR
输出total
This loop adds numbers 1 to 5. When count=1, total=1; count=2, total=3; count=3, total=6; count=4, total=10; count=5, total=15. The final OUTPUT displays 15. Pseudocode is a way to plan logic before coding in a specific language.
这个循环将数字1到5累加。当count=1，total=1；count=2，total=3；count=3，total=6；count=4，total=10；count=5，total=15。最终输出显示15。伪代码是在用特定语言编码前规划逻辑的一种方式。
8. Online Safety and Personal Information | 网络安全与个人信息
Question: A stranger in an online game asks for your real name, school, and address. Explain why you should not share these details and what you should do.
题目：一位网络游戏中的陌生人询问你的真实姓名、学校和住址。请解释为什么不应分享这些信息，以及你应该怎么做。
Personal information can be used to identify, locate, or contact you. Sharing it with strangers puts you at risk of cyberbullying, identity theft, or even physical danger. You should never share these details. Instead, block the user, tell a trusted adult, and report the person to the game platform’s safety tools.
个人信息可被用来识别、定位或联系你。与陌生人分享会使你面临网络欺凌、身份盗用甚至人身危险。你绝不应分享这些信息。相反，应屏蔽该用户，告知信任的成年人，并通过游戏平台的安全工具举报此人。
9. Digital Footprint and Password Security | 数字足迹与密码安全
Question: What is a digital footprint? Give one reason why a strong password is important for protecting your digital footprint.
题目：什么是数字足迹？给出一个理由，说明强密码对保护数字足迹为何重要。
A digital footprint is the trail of data you leave behind when you use the internet – posts, photos, comments, and even websites you visit. A strong password prevents unauthorised people from accessing your accounts and misusing your online identity. Without it, someone could post harmful content in your name, damaging your footprint and reputation.
数字足迹是你使用互联网时留下的数据痕迹——包括帖子、照片、评论，甚至你访问的网站。强密码可以防止未经授权的人访问你的账户并滥用你的在线身份。没有强密码，他人可能冒用你的名义发布有害内容，损害你的足迹和声誉。
10. Copyright and Digital Citizenship | 版权与数字公民
Question: You find a great image on the internet and want to use it in a school project. Explain whether you can just copy it, and what being a good digital citizen means in this situation.
题目：你在网上发现一张很棒的图片，想在学校项目中使用。请解释你是否可以直接复制它，以及在这种情况下，做一名优秀数字公民意味着什么。
Most online content is protected by copyright. Simply copying an image without permission may be illegal. Good digital citizenship means respecting the creator’s rights. You should look for images labelled for reuse (such as Creative Commons) or ask the owner for permission. Always give credit by citing the source.
大多数在线内容受版权保护。未经许可直接复制图片可能违法。优秀的数字公民意味着尊重创作者的权利。你应该寻找标记为可复用（如知识共享许可）的图片，或者征求所有者许可。始终注明出处以表感谢。
11. Troubleshooting a Simple Program | 简单程序排错
Question: A block-based program is supposed to make a sprite walk 10 steps and then say ‘Hello’, but the sprite says ‘Hello’ without moving. What is the likely error and how would you fix it?
题目：一个基于积木的程序应让角色移动10步再说“你好”，但角色未移动就说出了“你好”。可能的错误是什么？你会如何修复？
The blocks might be in the wrong order. If the ‘say’ block appears before the ‘move’ block, the program executes the say command first. To fix it, drag the blocks so that the ‘move 10 steps’ block is above the ‘say Hello’ block. This ensures the sequence runs correctly. Sequencing errors like this are very common for beginners.
积木顺序可能错误。如果“说话”积木在“移动”积木之前，程序就会先执行说话命令。修复方法是将积木拖放，使“移动10步”积木位于“说你好”积木之上。这样能保证顺序正确。这类顺序错误在初学者中非常常见。
12. Understanding Networks and the Internet | 理解网络与互联网
Question: What is the difference between the World Wide Web and the internet? Give one example of how you use each.
题目：万维网与互联网之间有何区别？各举一个使用它们的例子。
The internet is the global network of computers connected by cables, satellites, and wireless technology. The World Wide Web is a collection of web pages and resources accessed over the internet using a browser. An example of using the internet is sending an email; an example of using the web is viewing a website like aleveler.com. They are often confused, but the web runs on top of the internet.
互联网是由电缆、卫星和无线技术连接起来的全球计算机网络。万维网是通过浏览器在互联网上访问的网页和资源的集合。使用互联网的例子是发送电子邮件；使用万维网的例子是浏览像 aleveler.com 这样的网站。两者常被混淆，但万维网运行在互联网之上。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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