📚 Year 7 WJEC Computing: Unit Test Mock Paper Breakdown | WJEC 七年级计算机单元测试模拟卷解析
Welcome to our detailed walkthrough of a Year 7 WJEC Computing unit test mock paper. This guide breaks down each question type, explains the correct answers, and highlights common mistakes. It covers hardware, software, data representation, networks, programming in Scratch, and e-safety — all key topics in the WJEC KS3 curriculum. Whether you are revising for an upcoming test or simply want to build confidence, this step‑by‑step analysis will help you understand what examiners expect and how to earn full marks.
欢迎阅读我们为 WJEC 七年级计算机单元测试模拟卷提供的详细解析。本指南将逐题拆解题型、讲解正确答案并指出常见错误。内容涵盖硬件、软件、数据表示、网络、Scratch 编程以及电子安全——全部是 WJEC 关键阶段三计算机课程的核心主题。无论你是在为即将到来的测验复习，还是只想建立信心，这篇逐步解析都能帮你理解考官的预期并拿到满分。
1. Question 1: Input Devices – Answer & Explanation | 题目1：输入设备 – 答案与解析
The first question in the mock paper was a multiple‑choice item: 'Which of the following is an input device? A) Monitor B) Keyboard C) Printer D) Speakers'
模拟卷第一道题是选择题：“以下哪项是输入设备？A) 显示器 B) 键盘 C) 打印机 D) 扬声器”
The correct answer is B: Keyboard. An input device is any piece of hardware that sends data into a computer. The keyboard lets you enter text, numbers and commands. Monitors, printers and speakers are output devices — they receive data from the computer and present it to you as pictures, hard copies or sound. A common trap is thinking a touch screen is only an input device, but a monitor alone is an output device.
正确答案是 B: 键盘。输入设备是将数据送入计算机的任何硬件。键盘可让你输入文字、数字和指令。显示器、打印机和扬声器都是输出设备——它们从计算机接收数据，然后以图像、纸质副本或声音的形式呈现给你。常见的陷阱是以为触摸屏只是输入设备，但单独的显示器是输出设备。
2. Question 2: Output Devices – Spotting the Right Hardware | 题目2：输出设备 – 识别正确的硬件
The second question reversed the idea: 'Which of these is an output device? A) Mouse B) Scanner C) Monitor D) Microphone'
第二道题反过来问：“以下哪项是输出设备？A) 鼠标 B) 扫描仪 C) 显示器 D) 麦克风”
The correct choice is C: Monitor. A monitor displays the results of processing. The mouse and microphone send data into the computer (input), and a scanner captures images and turns them into digital data, so it too is an input device. Remember: the direction of data flow determines whether a device is input or output.
正确选项是 C: 显示器。显示器展示处理结果。鼠标和麦克风把数据送入计算机（输入），扫描仪捕捉图像并将其转换为数字数据，因此它也是输入设备。请记住：数据流动的方向决定设备是输入还是输出。
3. Question 3: What Does CPU Stand For? | 题目3：CPU 代表什么？
Question 3 tested terminology: 'What does CPU stand for? A) Central Processing Unit B) Computer Personal Unit C) Central Program Unit D) Core Processor Unit'
第三题考查术语：“CPU 代表什么？A) Central Processing Unit B) Computer Personal Unit C) Central Program Unit D) Core Processor Unit”
The right answer is A: Central Processing Unit. The CPU is often called the 'brain' of the computer. It carries out instructions and processes data. Distractors like 'Core Processor Unit' sound plausible but are not the correct full form. Always learn the exact names of key components.
正确答案是 A：中央处理器（Central Processing Unit）。CPU 常被称为计算机的“大脑”。它执行指令并处理数据。像“Core Processor Unit”这样的干扰项听起来合理，但不是正确的全称。一定要记住关键部件的确切名称。
4. Question 4: What Is a Computer Network? | 题目4：什么是计算机网络？
Question 4 asked: 'A school computer network allows users to: A) Share files and printers B) Only play online games C) Keep all work on a single local disk D) Prevent any communication'
第四题提问：“学校计算机网络允许用户：A) 共享文件和打印机 B) 只玩在线游戏 C) 将所有工作保存在单个本地磁盘上 D) 阻止一切通信”
The correct option is A: Share files and printers. A network connects two or more computers so they can share resources (files, printers, internet connections) and communicate. Options B and D are too narrow or false; a network does many things. Option C describes a non‑networked, standalone computer. Understanding the purpose of a network is fundamental for this exam.
正确选项是 A：共享文件和打印机。网络将两台或更多计算机连接起来，使它们可以共享资源（文件、打印机、互联网连接）并相互通信。选项 B 和 D 过于狭隘或错误；网络能做很多事情。选项 C 描述的是未联网的单机。理解网络的目的是本考试的基础。
5. Question 5: Binary Conversion – Decimal to Binary | 题目5：二进制转换 – 十进制转二进制
Question 5 assessed data representation: 'What is the binary representation of the decimal number 5? A) 101 B) 110 C) 100 D) 111'
第五题考查数据表示：“十进制数 5 的二进制表示是什么？A) 101 B) 110 C) 100 D) 111”
The correct binary is 101. Binary uses only 0s and 1s. The place values for a 3‑bit number are 4, 2, 1. To make 5 we need one 4 (1), zero 2s (0) and one 1 (1), giving 101. Option B (110) is 6, C (100) is 4, and D (111) is 7. Laying out place values like a small table can prevent mistakes.
正确的二进制数是 101。二进制只使用 0 和 1。三位二进制数的位值依次为 4, 2, 1。要组成 5，我们需要一个 4 (1)、零个 2 (0) 和一个 1 (1)，即 101。选项 B (110) 是 6，C (100) 是 4，D (111) 是 7。像小表格那样列出位值可以避免错误。
6. Question 6: Strong Password Rules – Short Answer | 题目6：强密码规则 – 简答题
Question 6 was a short‑answer item: 'Give two rules for creating a strong password.'
第六题是简答题：“给出创建强密码的两条规则。”
A model answer would state: 1. Use a mix of uppercase and lowercase letters, numbers, and symbols. 2. Make it at least eight characters long and avoid personal information like your name or birth date. Examiners look for practical safety advice. Saying simply 'make it hard' does not earn marks; you must be specific about length and character variety.
一份标准答案可以是：1. 混合使用大小写字母、数字和符号。2. 长度至少八个字符，并避免使用姓名或生日等个人信息。 考官看重实用的安全建议。仅说“让它难猜”不会得分；必须具体说明长度和字符种类。
7. Question 7: Name Two Input Devices and Their Uses | 题目7：写出两个输入设备及其用途
This short‑answer question asked: 'Name two input devices and describe what each one is used for.'
这道简答题要求：“写出两个输入设备并分别描述其用途。”
Two strong examples are: Keyboard – used to enter text, numbers and commands into a computer. Microphone – captures sound and converts it into digital audio signals that the computer can process. Other acceptable answers include mouse (pointing and clicking), touchscreen (direct finger input) or webcam (capturing video). Always pair a device with its main function to gain the full mark.
两个有力的例子是：键盘——用于将文字、数字和指令输入计算机。麦克风——捕捉声音并将其转换为计算机可处理的数字音频信号。其他可接受的答案包括鼠标（指向和点击）、触摸屏（直接手指输入）或网络摄像头（捕捉视频）。一定要将设备与其主要功能配对才能获得满分。
8. Question 8: Hardware vs Software – Explain the Difference | 题目8：硬件与软件 – 说明区别
Question 8 asked: 'Explain the difference between hardware and software. Give one example of each.'
第八题提问：“解释硬件和软件的区别，并各举一例。”
The key distinction is: Hardware is the physical parts of a computer that you can touch, such as a monitor, keyboard or motherboard. Software is the set of instructions that tells the hardware what to do; it cannot be physically touched. Examples: hardware – hard disk drive; software – a web browser. A common mistake is naming a device like a printer as software; reinforce that if you can hold it, it is hardware.
关键区别在于：硬件是计算机中你可以触摸到的物理部件，比如显示器、键盘或主板。软件是指挥硬件如何工作的一组指令，无法被实际触摸。举例：硬件——硬盘驱动器；软件——网页浏览器。一个常见错误是把打印机当作软件；请牢记：如果你能拿在手里，它就是硬件。
9. Question 9: Scratch Sequencing – Predicting the Output | 题目9：Scratch 顺序程序 – 预测输出
This programming item showed a simple Scratch script: 'When green flag clicked, say "Hello" for 2 seconds, then move 10 steps.' The question asked: 'What will the sprite say and do?'
这道编程题展示了一段简单的 Scratch 脚本：“当绿旗被点击，说‘Hello’ 2 秒，然后移动 10 步。” 提问：“角色会说什么并做什么？”
The sprite will display the word 'Hello' in a speech bubble for 2 seconds and then glide 10 steps in its current direction. The script runs in order, from top to bottom, illustrating the computing concept of sequence. Even if 'move 10 steps' is not visible on screen because the glide is instant, the expected output is the 'Hello' bubble followed by a change in position.
角色会在对话气泡中显示词语 “Hello” 持续 2 秒，然后沿当前方向移动 10 步。脚本按照从上到下的顺序执行，体现了顺序这一计算思维概念。即使因为滑行瞬间完成而看不见实际移动，预期的输出仍是 “Hello” 气泡以及随后位置的变化。
10. Question 10: Debugging a Scratch Loop | 题目10：调试 Scratch 循环
Question 10 gave a buggy script: 'When green flag clicked, forever move 10 steps' with no wait block. The task was: 'Identify the problem and suggest how to fix it.'
第十题提供了一段有错误的脚本：“当绿旗被点击，重复执行移动 10 步”，但没有等待积木。任务是：“找出问题并建议如何修正。”
The issue is that the forever loop runs so fast the sprite appears to flicker or instantly leap off the stage. The fix is to insert a wait block (e.g., 'wait 0.1 seconds') inside the loop after the motion command. This slows down the loop enough to make the movement smooth and visible. Debugging like this reinforces the need to control timing in animation and game loops.
问题在于这个无限循环运行得太快，导致角色看起来闪烁不定或瞬间冲出舞台。修正方法是在循环内部的移动积木之后插入一个等待积木（如“等待 0.1 秒”）。这样能减慢循环速度，让移动变得平顺可见。像这样的调试过程强化了在动画和游戏循环中控制时间的必要性。
11. Question 11: Extended Writing – Why Keep Software Updated? | 题目11：扩展写作 – 为什么要保持软件更新？
The first extended‑writing task asked: 'Explain why it is important to install software updates. Give at least two reasons.'
第一道扩展写作题提问：“解释安装软件更新的重要性。请至少给出两条理由。”
A high‑scoring answer would mention: Security patches — updates fix vulnerabilities that hackers could exploit, protecting your data. Bug fixes — developers correct errors that cause crashes or strange behaviour. New features — updates can add extra functions and improve performance. Mentioning that out‑of‑date software can stop working with newer apps shows deeper understanding. Always link security updates to the concept of e‑safety.
一份高分答案会提及：安全补丁——更新可修复黑客可能利用的漏洞，保护你的数据。错误修复——开发人员会纠正导致崩溃或异常行为的错误。新功能——更新可以添加额外功能并提升性能。提到过时的软件可能无法与新应用协同工作会展示更深层的理解。务必把安全更新与电子安全的概念联系起来。
12. Question 12: Extended Writing – The Role of the Operating System | 题目12：扩展写作 – 操作系统的作用
The final extended question read: 'Describe the role of an operating system (OS). Include at least three functions it performs.'
最后一道扩展题要求：“描述操作系统的作用。至少写出它执行的三项功能。”
Aim to cover these responsibilities: Managing hardware — the OS controls input, output and storage devices, acting as a bridge between software and hardware. Providing a user interface — it gives you a way to interact with the computer, such as a graphical desktop or touch screen. Running applications — it loads programs into memory and allocates CPU time. File management — it organises, saves and retrieves files on disk. The answer should show that the OS is the essential software that makes a computer usable.
目标是要涵盖以下这些职责：管理硬件——操作系统控制输入、输出和存储设备，充当软件与硬件之间的桥梁。提供用户界面——它为你提供与计算机交互的途径，例如图形桌面或触摸屏。运行应用程序——它将程序加载到内存中并分配 CPU 时间。文件管理——它在磁盘上组织、保存和检索文件。答案应表明操作系统是使计算机能够被使用的最基本软件。
Published by TutorHao | Computing Revision Series | aleveler.com
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