Year 9 CCEA Computer Science: Mock Unit Test Analysis | Year 9 CCEA 计算机：单元测试模拟卷解析

📚 Year 9 CCEA Computer Science: Mock Unit Test Analysis | Year 9 CCEA 计算机：单元测试模拟卷解析

This article provides a complete walkthrough of a mock unit test designed for Year 9 CCEA Computer Science. By working through each question and its detailed explanation in both English and Chinese, you will strengthen your understanding of core topics such as algorithms, data representation, hardware, programming, networks and digital ethics. Use this resource to check your knowledge and build confidence before a real assessment.

本文提供了一份专门为 Year 9 CCEA 计算机科学设计的单元测试模拟卷全程解析。通过逐题讲解和中英文对照的详细说明，你将巩固对算法、数据表示、硬件、编程、网络和数字伦理等核心主题的理解。请把这份资料当作自我检测和考前建立信心的工具。

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1. Algorithm Analysis with Flowcharts | 流程图算法分析

Question: Study the flowchart described below. The process starts by inputting a number x. A decision tests whether x is exactly divisible by 2 (x is even). If the answer is Yes, the output is x ÷ 2. If the answer is No, the output is (x × 2) + 1. Suppose the input is 7. What will the output be?

题目： 请研究下面描述的流程图。从输入一个数字 x 开始。一个判断框检测 x 是否能被 2 整除（x 是否为偶数）。如果结果为“是”，则输出 x ÷ 2；如果为“否”，则输出 (x × 2) + 1。假设输入为 7，输出会是什么？

Since 7 is odd (not divisible by 2), we follow the ‘No’ branch. The calculation becomes (7 × 2) + 1 = 14 + 1 = 15. Therefore, the output is 15.

因为 7 是奇数（不能被 2 整除），我们沿“否”分支执行。计算过程为 (7 × 2) + 1 = 14 + 1 = 15。因此，输出为 15。

Flowcharts are a visual way to represent algorithms. Correctly tracing the decision symbol and the sequence of steps is essential for predicting a program’s behaviour without running it on a computer.

流程图是表示算法的一种可视化方式。正确追踪判断符号和步骤顺序，对于在不运行程序的情况下预测程序行为至关重要。

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2. Binary and Decimal Conversion | 二进制与十进制转换

Question: Convert the decimal number 45 into an 8-bit binary number. Then convert the binary number 11001₂ into its decimal equivalent.

题目： 将十进制数 45 转换为一个 8 位二进制数。再将二进制数 11001₂ 转换为其对应的十进制数。

For 45, we repeatedly divide by 2 and record the remainders: 45 ÷ 2 = 22 remainder 1, 22 ÷ 2 = 11 remainder 0, 11 ÷ 2 = 5 remainder 1, 5 ÷ 2 = 2 remainder 1, 2 ÷ 2 = 1 remainder 0, 1 ÷ 2 = 0 remainder 1. Reading the remainders backwards gives 101101. As an 8-bit number we pad with leading zeros: 00101101₂.

对于 45，我们反复除以 2 并记录余数：45 ÷ 2 = 22 余 1，22 ÷ 2 = 11 余 0，11 ÷ 2 = 5 余 1，5 ÷ 2 = 2 余 1，2 ÷ 2 = 1 余 0，1 ÷ 2 = 0 余 1。从下往上读取余数得到 101101。作为 8 位二进制数，我们在高位补零：00101101₂。

For 11001₂, we multiply each bit by its place value: 1×2⁴ + 1×2³ + 0×2² + 0×2¹ + 1×2⁰ = 16 + 8 + 0 + 0 + 1 = 25. So the decimal value is 25.

对于 11001₂，我们将每一位乘以其位权：1×2⁴ + 1×2³ + 0×2² + 0×2¹ + 1×2⁰ = 16 + 8 + 0 + 0 + 1 = 25。所以十进制值为 25。

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3. Classifying Hardware Components | 硬件组件分类

Question: A list of hardware components is shown below: keyboard, monitor, printer, USB flash drive, CPU. Categorise each component as an input device, an output device, a storage device or a processing device.

题目： 以下是硬件组件列表：键盘、显示器、打印机、USB 闪存盘、CPU。请将每个组件分类为输入设备、输出设备、存储设备或处理设备。

The keyboard allows the user to enter data, so it is an input device. The monitor displays visual information, making it an output device. The printer produces physical copies of documents, so it is also an output device. A USB flash drive stores files and data permanently, so it is a storage device. The CPU (Central Processing Unit) carries out instructions and calculations, therefore it is a processing device.

键盘让用户输入数据，所以它是输入设备。显示器显示视觉信息，因此是输出设备。打印机生成文档的纸质副本，所以也是输出设备。USB 闪存盘永久存储文件和数据，因此是存储设备。CPU（中央处理器）执行指令和计算，因此是处理设备。

Knowing the function of each hardware category helps you understand how a computer system receives, processes, stores and outputs data during a typical task.

了解每个硬件类别的作用有助于你理解计算机系统在执行典型任务时如何接收、处理、存储和输出数据。

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4. System Software vs Application Software | 系统软件与应用软件

Question: Give one example of system software and explain its main purpose. Then give one example of application software and describe what it allows a user to do.

题目： 举出一个系统软件的例子，并解释它的主要用途。再举出一个应用软件的例子，并描述它允许用户做什么。

An operating system, such as Microsoft Windows or macOS, is system software. Its main purpose is to manage the computer’s hardware resources, run other programs, and provide a user interface. Without an operating system, a computer cannot function.

操作系统，如 Microsoft Windows 或 macOS，是系统软件。它的主要用途是管理计算机的硬件资源、运行其他程序并提供用户界面。没有操作系统，计算机将无法工作。

A word processor, like Microsoft Word, is application software. It allows users to create, edit, format and print text-based documents for schoolwork, reports or letters. Application software helps users perform specific tasks.

文字处理软件，如 Microsoft Word，是应用软件。它允许用户创建、编辑、排版和打印基于文本的文档，用于学校作业、报告或信件。应用软件帮助用户执行特定任务。

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5. Python Code Tracing | Python 代码跟踪

Question: Examine the following Python code snippet. Predict the exact output that will appear on the screen when it is executed.

题目： 检查下面的 Python 代码片段。预测执行后屏幕上会显示的准确输出。

for i in range(1, 4):
    print(i * i)

The function range(1, 4) generates the numbers 1, 2, and 3. The loop runs three times. In the first iteration, i is 1, so print(1 * 1) displays 1. The second iteration, i is 2, so print(2 * 2) displays 4. The third iteration, i is 3, so print(3 * 3) displays 9. Therefore, the output will be:

函数 range(1, 4) 生成数字 1、2 和 3。循环运行三次。第一次迭代，i 为 1，因此 print(1 * 1) 显示 1。第二次迭代，i 为 2，因此 print(2 * 2) 显示 4。第三次迭代，i 为 3，因此 print(3 * 3) 显示 9。所以输出将是：

1
4
9

Code tracing is a vital skill. You should pay attention to how the loop variable changes each time and what arithmetic expression is used inside the loop body.

代码追踪是一项关键技能。你应该注意循环变量在每次迭代时如何变化，以及循环体内使用了什么算术表达式。

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6. Understanding Local Area Networks | 理解局域网

Question: Explain what a Local Area Network (LAN) is and give a real-life example. State two advantages of using a LAN in a school.

题目： 解释什么是局域网 (LAN)，并举一个实际例子。说明在学校中使用局域网的兩個优势。

A LAN is a network that connects computers and devices over a small geographical area, such as a single building or campus. An example is the computer suite in a school library where all PCs are linked together. One advantage is that users can share hardware resources like printers, reducing costs. Another advantage is that files and learning materials can be stored on a central server and accessed by any authorised student, making collaboration easier.

局域网 (LAN) 是将计算机和设备连接在一个小的地理区域（如单栋建筑或校园）内的网络。一个例子是学校图书馆的计算机套间，所有 PC 都连接在一起。一個优势是用户可以共享打印机等硬件资源，从而降低成本。另一个优势是文件和学习材料可以存储在中央服务器上，供任何经授权的学生访问，使协作更加容易。

A LAN typically offers high data transfer speeds and is owned and managed by the organisation itself, unlike a Wide Area Network (WAN) that spans cities or countries.

局域网通常提供高数据传输速率，并由所属组织自身拥有和管理，这与跨越城市或国家的广域网 (WAN) 不同。

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7. Password Security and Phishing Awareness | 密码安全与防钓鱼意识

Question: List three rules for creating a strong password. Then read the following email excerpt and identify two signs that suggest it is a phishing attempt. “Dear User, Your account has been compromised. Click the link below immediately to restore access: http://secure-update.malicious.net. Act now or your data will be lost!”

题目： 列出创建强密码的三条规则。然后阅读下面的邮件摘录，指出两个表明它是网络钓鱼尝试的迹象。”亲爱的用户，您的账户已被盗用。请立即点击以下链接恢复访问权限：http://secure-update.malicious.net。马上行动，否则您的数据将丢失！”

Strong password rules: (1) Use at least eight characters. (2) Mix uppercase letters, lowercase letters, numbers and symbols (e.g. ‘P@ssw0rd!’). (3) Avoid personal information like your name or birthday, and do not reuse passwords across different accounts.

强密码规则：(1) 使用至少八个字符。(2) 混合使用大写字母、小写字母、数字和符号（例如 ‘P@ssw0rd!’）。(3) 避免使用姓名或生日等个人信息，并且不要在不同账户中重复使用密码。

The email shows two clear signs of phishing. First, it creates a sense of urgency by threatening data loss to make the recipient act without thinking. Second, the link address looks suspicious: the domain ‘malicious.net’ is not a legitimate banking or service provider domain. Legitimate organisations never ask you to click a link to verify your account in an unsolicited email.

该邮件显示了两个明显的钓鱼迹象。首先，它通过威胁数据丢失来制造紧迫感，让收件人不假思索地行动。其次，链接地址看起来可疑：域名 ‘malicious.net’ 并不是合法的银行或服务提供商域名。合法组织绝不会在未经请求的邮件中要求你点击链接验证账户。

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8. Computational Thinking: Decomposition | 计算思维：分解

Question: You are asked to write an algorithm to make a cheese and tomato sandwich. Use decomposition to break the task down into at least five smaller, ordered steps.

题目： 要求你编写一个制作奶酪番茄三明治的算法。请使用分解的方法将该任务拆分成至少五个有序的较小步骤。

Decomposition means breaking a large problem into smaller, manageable parts. A possible breakdown is: 1. Take two slices of bread from the packet. 2. Use a butter knife to spread butter on one side of each slice. 3. Place a slice of cheese on the buttered side of one piece of bread. 4. Wash a tomato and cut two thin slices, then lay them on top of the cheese. 5. Position the second slice of bread on top, buttered side down. 6. Cut the sandwich diagonally and serve.

分解意味着将一个大问题拆分成更小、可管理的部分。一种可能的分解是：1. 从包装袋中取出两片面包。2. 用黄油刀在每片面包的一面涂抹黄油。3. 在一片面包的黄油面上放一片奶酪。4. 清洗一个番茄并切兩个薄片，然后将它们放在奶酪上面。5. 将第二片面包覆盖在上面，黄油面朝下。6. 将三明治沿对角线切开并装盘。

By decomposing the task, we can focus on each action individually, making it easier to write precise instructions and to identify any missing steps before implementation.

通过分解任务，我们可以单独关注每个动作，从而更容易编写精确的指令，并在实施前发现任何遗漏的步骤。

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9. Debugging Syntax and Logic Errors | 调试语法与逻辑错误

Question: Below are two incorrect Python code snippets. Identify the type of error in each (syntax or logic) and explain how to fix it.

题目： 下面是两段错误的 Python 代码片段。指出每段的错误类型（语法或逻辑），并说明如何修正。

Snippet A: if score >= 50
print('Pass')
Snippet B: length = 10
width = 5
area = length + width
print(area)

In Snippet A, a colon ‘:’ is missing at the end of the if statement line. This is a syntax error because the code does not follow the correct Python grammar rules. The fix is to write if score >= 50:.

在片段 A 中，if 语句行末尾缺少冒号 ‘:’。这是一个语法错误，因为代码没有遵循正确的 Python 语法规则。修正方法是写成 if score >= 50:。

Snippet B calculates area by adding length and width instead of multiplying them. The program will run without crashing, but the result 15 is not the correct area of a rectangle. This is a logic error. The fix is to change the line to area = length * width, which would give the correct output 50.

片段 B 计算面积时，将长和宽相加而不是相乘。程序可以运行而不会崩溃，但结果 15 并不是矩形的正确面积。这是一个逻辑错误。修正方法是将该行改为 area = length * width，这样就会输出正确结果 50。

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10. Ethical Use of Digital Content | 数字内容的道德使用

Question: You find an ideal photograph on a website to include in your school project. Is it acceptable to use the image without checking its licence? Explain what you should do to respect copyright and why plagiarism is wrong.

题目： 你发现一张非常适合放入学校项目的照片，它来自某网站。直接使用该图片而不检查其许可证可以接受吗？解释你应该怎么做才能尊重版权，并说明为什么抄袭是错误的。

It is not acceptable to use the image without permission or without checking its copyright status. Most online images are protected by copyright, meaning the creator has exclusive rights over how they are used. To use an image properly, you should check for a licence such as Creative Commons, or use websites that offer royalty‑free images. Even then, you should cite the source to give credit to the original creator.

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Published by TutorHao | Year 9 Computer Science Revision Series | aleveler.com

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