📚 AQA Year 9 Computer Science: Complete Syllabus Breakdown | AQA 九年级计算机：课程大纲全面解析
Welcome to your comprehensive guide to the Year 9 AQA Computer Science syllabus. Whether you are just starting your computing journey or preparing for the transition to GCSE, this article unpacks every key topic, assessment method, and study strategy. We will explore how the syllabus is structured, what core concepts you must master, and how you can build a strong foundation for future success in computer science. Think of this as your roadmap through Year 9 – from understanding algorithms and programming to grasping how computers and networks operate in the modern world.
欢迎阅读 AQA 九年级计算机科学课程大纲全面指南。无论你刚刚开始学习计算机，还是正在为升入 GCSE 做准备，本文都将详细剖析每一个核心主题、评估方式和学习策略。我们将一起探索课程大纲的结构、必须掌握的关键概念，以及如何为将来在计算机科学领域取得成功打下坚实基础。可以把这篇文章看作你九年级学习的路线图——从理解算法和编程，到了解计算机和网络如何在现代世界中运行，你将无所不包。
1. The Year 9 AQA Computer Science Framework | 九年级 AQA 计算机课程整体框架
Year 9 AQA Computer Science serves as a bridge between Key Stage 3 fundamentals and the rigorous GCSE specification (8525). The curriculum is designed to build computational thinking, practical programming skills, and theoretical understanding of computer systems. Unlike earlier years, the content becomes more structured and begins to mirror the GCSE assessment objectives: AO1 (knowledge and understanding), AO2 (application), and AO3 (analysis and evaluation). Students typically have two to three lessons per week, with a strong emphasis on hands-on coding and problem‑solving.
九年级 AQA 计算机课程扮演着关键阶段 3 基础与严格的 GCSE 规范（代码 8525）之间的桥梁角色。课程旨在培养计算思维、实践编程技能以及对计算机系统的理论理解。与前几年不同，内容更加体系化，并开始呼应 GCSE 的评估目标：AO1（知识与理解）、AO2（应用）和 AO3（分析与评价）。学生通常每周有两到三节课，重点强调动手编码和解决问题。
The syllabus is not a fixed national curriculum for Year 9 but reflects common schemes of work adopted by schools following AQA’s GCSE pathway. Topics can be grouped into five broad strands: algorithms, programming, data representation, computer systems, and impacts of digital technology. Each strand is covered with increasing depth, preparing students for the terminal examinations and the non‑exam assessment (NEA) they will encounter in Years 10 and 11.
该课程大纲并非法定的九年级国家课程，而是遵循 AQA GCSE 路径的学校普遍采用的工作方案。主题可以归纳为五大板块：算法、编程、数据表示、计算机系统以及数字技术的影响。每个板块都会逐步深入，帮助学生为十和十一年级将面临的终结性考试和非考试评估（NEA）做好准备。
| Strand | Key Topics in Year 9 | GCSE Weighting |
|---|---|---|
| Algorithms | Flowcharts, pseudocode, sorting & searching algorithms | ~25% |
| Programming | Python basics, selection, iteration, data structures | ~35% |
| Data Representation | Binary, hexadecimal, images, sound, compression | ~15% |
| Computer Systems | Hardware, software, logic gates, fetch‑execute cycle | ~15% |
| Impacts of Technology | Ethics, cybersecurity, environmental issues | ~10% |
2. Computational Thinking and Algorithms | 计算思维与算法
At the heart of Year 9 is computational thinking – a problem‑solving approach that involves decomposition, pattern recognition, abstraction, and algorithm design. Students learn to break down complex tasks into smaller, manageable parts and represent solutions using flowcharts and pseudocode. These skills are not just academic; they mirror how software engineers design real‑world systems. For example, designing a simple app to calculate a student's average grade requires abstraction (ignoring irrelevant details) and a step‑by‑step plan.
九年级的核心是计算思维——一种包括分解、模式识别、抽象化和算法设计的问题解决方法。学生学习将复杂任务分解为更小、更易管理的部分，并用流程图和伪代码表示解决方案。这些技能不仅是学术性的，它们反映了软件工程师如何设计现实世界的系统。例如，设计一个计算学生平均成绩的简单应用就需要抽象化（忽略不相关细节）和逐步计划。
Flowcharts remain a key tool, using standard symbols such as ovals for start/end, parallelograms for input/output, and diamonds for decisions. Pseudocode in Year 9 follows a simplified version of AQA’s exam reference language, so students become comfortable with constructs like IF...ELSE, WHILE loops, and FOR loops long before the final examination. Emphasis is placed on tracing algorithms manually to predict their output – a skill that is frequently tested.
流程图仍然是一个关键工具，使用标准符号，如椭圆形表示开始/结束、平行四边形表示输入/输出、菱形表示判断。九年级的伪代码遵循 AQA 考试参考语言的简化版本，使学生早在最终考试之前就熟悉 IF...ELSE、WHILE 循环和 FOR 循环等结构。重点放在手动追踪算法以预测其输出——这是一项经常被考查的技能。
- Decomposition: Breaking a problem into sub‑problems, e.g., separating input validation from calculation in a grade‑averaging program.
- Pattern Recognition: Spotting similarities with known problems, such as recognising that a searching task resembles looking up a name in a sorted list.
- Abstraction: Filtering out unnecessary information; modelling a school timetable without including every student’s individual preferences.
- Algorithm Design: Creating clear, unambiguous steps, often expressed as structured pseudocode.
- 分解： 将问题拆分为子问题，例如在平均成绩计算程序中将输入验证与计算分开。
- 模式识别： 发现与已知问题的相似之处，比如识别出搜索任务类似于在有序列表中查找名字。
- 抽象化： 滤除不必要的信息；对学校时间表建模而不包含每个学生的个人偏好。
- 算法设计： 创建清晰、无歧义的步骤，通常用结构化伪代码表达。
3. From Flowcharts to Code: Introduction to Python | 从流程图到代码：Python 入门
n is the most widely adopted language in AQA schools, and Year 9 marks the move from block‑based programming to text‑ sk might be a temperature converter that reads a Celsius value and outputs Fahrenheit. The mathematical formula F = C × 9/5 + 32 is implemented using Python operators – a perfect blend of maths and computing.
Python 是 AQA 学校中采用最广泛的语言，九年级标志着从基于模块的编程向文本编码的转变。学生从基础开始：变量、数据类型（整数、浮点数、字符串、布尔值）以及简单的输入/输出。一个早期任务可能是编写温度转换器，读取摄氏温度值并输出华氏温度。数学公式 F = C × 9/5 + 32 使用 Python 运算符实现——这是数学和计算的完美结合。
Selection (if, elif, else) and iteration (while and for loops) form the backbone of early programming. Students learn to write programs that make decisions, such as a marks‑to‑grade converter that assigns A*, A, B, etc., based on thresholds. Iteration is reinforced through activities like generating multiplication tables or simulating a simple login system with a limited number of attempts. Debugging and testing become routine, using both print statements and IDE tools to trace variable values.
选择结构（if, elif, else）和循环（while 和 for 循环）构成了早期编程的主干。学生学习编写做出决策的程序，例如一个根据分数阈值分配 A*、A、B 等等级的成绩转换器。通过生成乘法表或模拟带有尝试次数限制的简单登录系统等活动，循环结构得到强化。调试和测试成为常规，学生使用打印语句和 IDE 工具追踪变量值。
| Concept | Python Example | GCSE Relevance |
|---|---|---|
| Variable assignment | score = 85 |
Storing data at runtime |
| Conditional statement | if score >= 90: |
Decision‑making in programs |
| For loop | for i in range(1, 11): |
Definite iteration |
| While loop | while attempts < 3: |
Condition‑controlled iteration |
4. Data Structures: Lists and Dictionaries | 数据结构：列表与字典
Once students are comfortable with basic data types, Year 9 introduces compound data structures – chiefly lists (called arrays in pseudocode) and dictionaries. A list in Python is an ordered, mutable collection, perfect for storing a sequence of student marks or the days of the week. Students learn to append, remove, and iterate over lists, often combining them with for loops to compute totals or find maximum values. Dictionaries, on the other hand, store key‑value pairs and are used to model real‑world data like a contacts book or a simple inventory system.
当学生对基本数据类型驾轻就熟后，九年级引入了复合数据结构——主要是列表（伪代码中称为数组）和字典。Python 中的列表是一个有序、可变的集合，非常适合存储一系列学生成绩或一周的天数。学生学习向列表追加、移除元素以及遍历列表，常常结合 for 循环来计算总和或查找最大值。另一方面，字典以键‑值对形式存储数据，用于模拟现实世界的数据，如通讯录或简单的库存系统。
Manipulating data structures also lays the groundwork for more advanced GCSE topics such as records and SQL databases. A typical Year 9 project might involve creating a program that stores student names and marks in parallel lists or a dictionary, allows the user to search for a student, and calculates the class average. Such tasks naturally lead to discussions about searching algorithms – linear search on unsorted data, and the concept of binary search on sorted data (though the latter is often saved for Year 10).
操作数据结构也为更高级的 GCSE 主题如记录和 SQL 数据库奠定了基础。一个典型的九年级项目可能涉及创建一个程序，用并行列表或字典存储学生姓名和成绩，允许用户搜索某个学生，并计算班级平均分。这类任务自然地引出关于搜索算法的讨论——在无序数据上进行线性搜索，以及有序数据上的二分搜索概念（尽管后者通常留到十年级）。
Example data structure in Python: student_grades = {'Alice':78, 'Bob':85, 'Charlie':90}
Python 数据结构示例：student_grades = {'Alice':78, 'Bob':85, 'Charlie':90}
5. Data Representation: Binary, Hex, and Beyond | 数据表示：二进制、十六进制及其他
Data representation is a cornerstone of the AQA syllabus. Year 9 starts by demystifying binary – why computers use base‑2, how to convert between binary and denary (decimal), and binary addition. Students must be fluent in converting 8‑bit binary numbers to denary and vice versa, as well as understanding the concept of overflow. Hexadecimal is introduced as a more human‑friendly way of representing binary, crucial for colour codes and memory addresses. Simple conversions between hex and binary (using nibbles) are practised regularly.
数据表示是 AQA 课程大纲的基石。九年级首先揭开二进制神秘面纱——为什么计算机使用二进制，如何在二进制和十进制之间转换，以及二进制加法。学生必须能够熟练地进行 8 位二进制数与十进制数的相互转换，并理解溢出的概念。十六进制随后引入，作为一种更人性化的二进制表示方式，对颜色代码和内存地址至关重要。十六进制与二进制之间的简单转换（利用半字节）需经常练习。
Moving beyond numbers, Year 9 covers how text is represented using character sets – initially ASCII, then the need for Unicode. Images are explained in terms of pixels and colour depth; students learn to calculate file sizes for a bitmap image given width, height, and colour depth. Sound representation touches on sampling rates and bit depth, and the idea that higher quality means larger file sizes. Compression (lossy vs lossless) is introduced conceptually, often through examples like JPEG vs PNG images or ZIP files. Although the calculations might seem challenging, consistent practice with worksheets makes them second nature.
除了数字，九年级还涵盖如何使用字符集表示文本——先是 ASCII，然后是 Unicode 的需求。图像用像素和色深来解释；学生学习根据宽度、高度和色深计算位图图像的文件大小。声音表示涉及采样率和位深度，并说明高质量意味着更大的文件大小。压缩（有损与无损）以概念方式引入，通常通过诸如 JPEG 与 PNG 图像或 ZIP 文件等实例进行。尽管这些计算可能看起来颇具挑战，但通过工作纸的持续练习，它们会变得得心应手。
File size (bits) = width × height × colour depth
文件大小（位）= 宽度 × 高度 × 色深
6. Computer Systems: Inside the Box | 计算机系统：机箱内部
Understanding the components that make up a computer is essential. Year 9 revisits the CPU, main memory, and secondary storage, but with greater technical detail. Students learn the fetch‑decode‑execute cycle step by step, identifying the role of the program counter, MAR, MDR, CU, and ALU. Von Neumann architecture is introduced as the blueprint for most modern computers, and the concept of stored program is discussed. These low‑level ideas can be abstract, so teachers often use the analogy of a chef (the CPU) following a recipe (program) stored in the cupboard (memory).
理解组成计算机的组件至关重要。九年级重新涉及 CPU、主存储器和辅助存储，但会带有更多技术细节。学生逐步学习取指‑解码‑执行周期，识别程序计数器、MAR、MDR、控制单元和 ALU 的角色。冯·诺依曼体系结构作为大多数现代计算机的蓝图被引入，同时讨论存储程序的概念。这些底层思想可能很抽象，因此教师常用厨师（CPU）按照存放在柜子（内存）里的食谱（程序）做菜的比喻。
Logic gates are another new topic. Students are expected to know the truth tables and symbols for AND, OR, and NOT gates, and to combine them into simple logic circuits. Boolean expressions like A AND (B OR NOT C) are evaluated and drawn. These concepts directly support the GCSE understanding of how digital circuits make decisions. Additionally, the syllabus covers secondary storage types – magnetic, optical, and solid state – comparing their capacities, speeds, and uses. Factors like portability, durability, and cost are weighed in context of cloud storage and physical drives.
逻辑门是另一个新主题。学生需要知道 AND、OR 和 NOT 门的真值表与符号，并将它们组合成简单的逻辑电路。对诸如 A AND (B OR NOT C) 这样的布尔表达式进行求值和绘制。这些概念直接支持 GCSE 对数字电路如何做出决策的理解。此外，课程大纲还涵盖辅助存储类型——磁介质、光介质和固态存储——比较它们的容量、速度及用途。便携性、耐用性和成本等因素在云存储和物理驱动器的背景下被权衡。
7. Networks and the Internet | 网络与互联网
In an increasingly connected world, Year 9 students must grasp how computers communicate. The syllabus includes network topologies (star, bus, mesh), transmission media (wired and wireless), and protocols such as HTTP, HTTPS, FTP, and TCP/IP. Students learn that the internet is a global network of networks, and the World Wide Web is a collection of web pages accessed via the internet. The client‑server model is introduced along with the concept of IP addresses and the need for DNS to convert human‑readable URLs into machine‑readable IP addresses.
在一个日益互联的世界中，九年级学生必须掌握计算机如何通信。课程大纲包括网络拓扑（星型、总线型、网状）、传输介质（有线和无线）以及诸如 HTTP、HTTPS、FTP 和 TCP/IP 等协议。学生学习到互联网是一个全球性网络之网，而万维网是通过互联网访问的网页集合。客户‑服务器模型以及 IP 地址的概念被引入，同时解释为什么需要 DNS 将人类可读的 URL 转换为机器可读的 IP 地址。
Network security is a recurring theme. Students explore common threats – malware, phishing, denial‑of‑service attacks – and defences such as firewalls, encryption, and authentication. The importance of robust passwords and two‑factor authentication is reinforced through practical activities, sometimes using simplified network simulation tools. The layered approach of TCP/IP stack (application, transport, internet, link) is described at a high level, laying the groundwork for the more detailed treatment in GCSE. These lessons often spark rich discussions about privacy and the digital footprint.
网络安全是一个反复出现的主题。学生探索常见威胁——恶意软件、网络钓鱼、拒绝服务攻击——以及诸如防火墙、加密和身份验证等防御措施。通过有时使用简化网络模拟工具的实践活动，加强学生对强健密码和双因素认证重要性的理解。TCP/IP 协议栈（应用层、传输层、网际层、网络接入层）的分层方法在较高层次上描述，为 GCSE 更详细的处理奠定基础。这些课程常常引发关于隐私和数字足迹的丰富讨论。
8. Ethical, Legal and Environmental Impacts | 伦理、法律及环境影响
AQA places strong emphasis on the wider implications of computing. In Year 9, students are introduced to key legislation such as the Data Protection Act, Computer Misuse Act, and Copyright, Designs and Patents Act. They learn to distinguish between ethical, legal, and cultural issues, applying these categories to case studies. For example, a company collecting customer data without consent raises both legal (Data Protection Act) and ethical concerns. Similarly, the rise of AI and automation prompts debate about job displacement versus increased efficiency.
AQA 非常重视计算机领域的广泛影响。九年级向学生介绍关键立法，如《数据保护法》、《计算机滥用法》和《版权、设计与专利法》。他们学习区分伦理、法律和文化问题，并将这些分类应用于案例研究。例如，一家公司在未经同意的情况下收集客户数据会引发法律（《数据保护法》）和伦理双重问题。同样，人工智能和自动化的兴起引发了关于工作岗位流失与效率提升的辩论。
Environmental topics are also part of the syllabus: the energy consumption of data centres, the problem of e‑waste, and how technology can both harm and help the environment (e.g., smart grids vs mining for rare minerals). Students may research the lifecycle of a smartphone and present findings. This strand encourages critical thinking and often links to other subjects such as PSHE and geography. In preparation for GCSE extended‑writing questions, Year 9 pupils practise structuring balanced arguments with evidence, a skill that extends well beyond the computer lab.
环境主题也是课程大纲的一部分：数据中心的能源消耗、电子垃圾问题，以及技术如何既能损害环境又能帮助环境（例如智能电网与稀土矿物开采）。学生可能会研究一部智能手机的生命周期并展示发现。这一板块鼓励批判性思维，并常常与 PSHE 和地理等其他科目相关联。为准备 GCSE 的扩展写作题，九年级学生练习用证据构建平衡的论点，这项技能远不止于计算机实验室。
9. Software Development Lifecycle and Testing | 软件开发生命周期与测试
Year 9 introduces the concept of a systematic approach to software creation, often through the waterfall model or a simplified agile cycle. Stages such as requirements analysis, design, implementation, testing, and maintenance are discussed. Students learn that testing is not an afterthought but an integral part of development. They write test plans with normal, boundary, and erroneous data, and then execute those tests on their own programs. A practical task might involve developing a quiz game, where the test plan ensures the scoring works correctly and invalid inputs are handled gracefully.
九年级引入了系统化软件创建方法的概念，通常通过瀑布模型或简化的敏捷周期来讲解。需求分析、设计、实现、测试和维护等阶段被讨论。学生学到测试不是事后考虑而是开发的有机组成部分。他们编写包含正常、边界和错误数据的测试计划，并在自己的程序上执行这些测试。一个实践任务可能涉及开发一个问答游戏，其中测试计划确保评分正常工作且无效输入得到妥善处理。
Debugging techniques are sharpened: reading error messages, using breakpoints, and stepping through code. The difference between syntax errors, logic errors, and runtime errors is made explicit. By the end of Year 9, students should be able to explain why a program fails and propose a fix – a clear link to AO3 evaluation skills. Version control is touched upon lightly, perhaps through collaborative projects using platforms like repl.it or GitHub Classroom, fostering teamwork and professional practice early on.
调试技巧得到强化：阅读错误消息、使用断点以及单步执行代码。语法错误、逻辑错误和运行时错误之间的区别被明确指出。到九年级末，学生应能解释程序为何失败并提出修复方案——这与 AO3 评价技能明显关联。版本控制被简单提及，也许通过使用 repl.it 或 GitHub Classroom 等平台的协作项目，尽早培养团队合作和专业实践。
10. Assessment Methods in Year 9 | 九年级的评估方式
Schools using AQA’s GCSE pathway typically design internal assessments for Year 9 that mirror the GCSE format. This usually includes a written paper at the end of the year and ongoing practical programming assessments. The written paper may contain multiple‑choice questions, short‑answer questions, and one or two extended‑writing tasks, covering both theory and application. Questions often present pseudocode or a scenario and ask students to complete, correct, or trace the algorithm. Sample question: "A program stores the names of students who have passed a test. Design an algorithm to count how many passed. Use pseudocode or a flowchart."
使用 AQA GCSE 路径的学校通常会设计仿照 GCSE 格式的九年级内部评估。这通常包括年末的笔试和持续的实践编程评估。笔试可能包含选择题、简答题以及一两道扩展写作题，涵盖理论和应用。题目常常给出伪代码或一个场景，并要求学生完成、纠正或追踪算法。样题示例："一个程序存储了通过测验的学生姓名。设计一个算法来统计通过的人数。使用伪代码或流程图。"
Practical assessments focus on a small‑scale programming project, often completed over several lessons. Marks are awarded for functional code, appropriate use of data structures, user friendliness, and thorough testing. Feedback is aligned with GCSE criteria so students become familiar with the language of exam mark schemes. Regular low‑stakes quizzes and homework also check understanding of key theory, and many schools use online platforms like Seneca or Isaac Computer Science to reinforce learning. Parents can expect to see a mixture of effort and attainment grades on reports.
实践评估集中在一个小规模编程项目上，通常跨越多节课完成。评分根据功能完整的代码、适当的数据结构使用、用户友好性以及充分的测试。反馈与 GCSE 标准对齐，使学生熟悉考试评分方案的语言。定期的低利害测验和家庭作业也检查关键理论的理解，许多学校使用 Seneca 或 Isaac Computer Science 等在线平台强化学习。家长可以预期在成绩报告中看到努力程度和学业水平的混合等级。
11. Study Tips and Recommended Resources | 学习技巧与推荐资源
Success in Year 9 Computer Science requires a blend of regular coding practice and consistent theory revision. Try the following strategies:
- Little and often: Spend 15–20 minutes coding every day, not just in lessons. Use online platforms like Codecademy or CodingBat for Python exercises.
- Make flashcards: For theory topics – binary conversions, key definitions (e.g., algorithm, abstraction), and legislation – use physical cards or apps like Quizlet.
- Teach someone else: Explaining fetch‑execute cycle or how DNS works to a family member reinforces your own understanding.
- Past paper questions: Although GCSE‑specific, practising earlier sections of AQA 8525 papers can build familiarity with style and difficulty.
在九年级计算机科学中取得成功需要定期编码练习和持续的理论复习相结合。尝试以下策略：
- 少量多次： 每天花 15 到 20 分钟编码，而不仅限于课堂。使用如 Codecademy 或 CodingBat 等在线平台进行 Python 练习。
- 制作抽认卡： 对于理论主题——二进制转换、关键定义（如算法、抽象化）和立法——使用实体卡片或 Quizlet 等应用。
- 教给别人： 向家人解释取指‑执行周期或 DNS 如何工作能巩固你自己的理解。
- 往年试卷题： 尽管是 GCSE 专用，练习 AQA 8525 试卷的早期部分可以让你熟悉题目风格和难度。
Recommended resources include the BBC Bitesize Computer Science KS3 and GCSE sections, which align well with AQA. The 'Python for Everybody' website offers free interactive tutorials, and Craig 'n' Dave videos break down every topic into bite‑sized chunks with memorable analogies. For deeper reading, the 'AQA GCSE Computer Science' textbook by Robson and Heathcote is often used from Year 9 onwards. Remember, the key is understanding, not just memorising – try to apply concepts to real‑world examples whenever possible.
推荐资源包括 BBC Bitesize Computer Science KS3 和 GCSE 部分，它们与 AQA 大纲高度契合。"Python for Everybody" 网站提供免费的互动教程，而 Craig 'n' Dave 视频将每个主题分解为带有生动类比的小节。若想深入阅读，Robson 和 Heathcote 编写的《AQA GCSE 计算机科学》教材通常从九年级开始使用。请记住，关键在于理解而不只是记忆——尽可能将概念应用于现实世界的例子。
12. Bridging the Gap to GCSE Computer Science | 衔接 GCSE 计算机科学
Year 9 is the launchpad for the rigour of GCSE. By the end of the year, students should be confident in writing small‑ to medium‑sized Python programs independently, converting number bases fluently, and describing how a computer works at the hardware level. The transition to Year 10 will deepen each of these strands and introduce more complex algorithms (merge sort, bubble sort), Boolean algebra, and advanced programming concepts like file handling and subprograms. The non‑examined assessment (NEA) in GCSE requires sustained coding over 20 hours, so building endurance and good coding habits now pays dividends.
九年级是迈向严格 GCSE 的起跳板。到学年结束时，学生应能自信地独立编写中、小规模 Python 程序，流畅地进行进制转换，以及在硬件层面描述计算机如何工作。进入十年级后，每个板块都将加深，并引入更复杂的算法（归并排序、冒泡排序）、布尔代数以及诸如文件处理和子程序等高级编程概念。GCSE 的非考试评估（NEA）要求持续 20 小时的编码，因此现在就建立毅力和良好的编码习惯将带来丰厚回报。
Above all, cultivate curiosity. The most successful computer science students are those who tinker, break things, and ask "what if?". Whether it is building a simple game, automating a spreadsheet task, or exploring how encryption keeps messages secret, every bit of exploration feeds back into your studies. Use this year to discover what excites you about computing – it will make the next two years not just manageable, but truly enjoyable.
最重要的是，培养好奇心。最成功的计算机科学学生是那些摆弄事物、打破常规并问"如果这样会怎样"的人。无论是编写一个简单游戏、自动化电子表格任务，还是探索加密如何为消息保密，每一次探索都会反馈到你的学业中。利用今年发现计算机科学中使你兴奋的部分——它将使接下来两年不仅应付自如，而且真正充满乐趣。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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