📚 Year 11 CIE Science: Extended Writing Framework and Model Answers | Year 11 CIE 科学：扩展写作框架与范文
In CIE IGCSE Science (Co-ordinated Sciences or separate Biology, Chemistry, Physics), 6-mark questions often require extended writing. You must construct a logical, evidence-based answer using correct scientific terminology. This article provides a clear framework and annotated model answers to help you consistently score full marks on these high-value questions.
在CIE IGCSE科学（综合科学或单独的物理、化学、生物）考试中，6分题通常要求扩展写作。你必须用正确的科学术语构建逻辑清晰、基于证据的答案。本文提供清晰的写作框架和带有批注的范文，帮助你在这些高分值题目中稳定获得满分。
1. Understanding Command Words in CIE Science | 理解CIE科学中的命令词
Command words dictate exactly what the examiner expects. 'Describe' means state what happens or what you observe, without giving a reason. 'Explain' requires a scientific reason, often using 'because' and linking cause to effect. 'Compare' asks for similarities and differences. 'Evaluate' means weigh up advantages and disadvantages to reach a conclusion. 'Suggest' implies applying your scientific knowledge to an unfamiliar context. Misreading the command word is the most common reason marks are lost.
命令词决定了考官的期望。"Describe"（描述）意味着陈述发生了什么或观察到什么，不需要给出原因。"Explain"（解释）要求给出科学原因，常使用"because"，并连接因果关系。"Compare"（比较）要求写出相似点和不同点。"Evaluate"（评价）意味着权衡优缺点并得出结论。"Suggest"（提出）意味着将科学知识应用到不熟悉的情境中。误读命令词是丢分最常见的原因。
| Command Word | Meaning | 提示 |
|---|---|---|
| Describe | 叙述特征/趋势 | 描述 |
| Explain | 给出科学原因 | 解释 |
| Compare | 相似与差异 | 比较 |
| Evaluate | 权衡并下结论 | 评价 |
| Suggest | 运用知识推断 | 建议/推断 |
2. Planning Your 6-Mark Answer | 规划你的6分答案
Always spend 1-2 minutes jotting down key points on the question paper. Identify the keywords in the question and link them to relevant syllabus topics. For a 6-mark question, aim for 5-6 distinct scientific points arranged in a logical sequence. A common structure is: state the observation, give the reason, provide a second linked point, and finish with a concluding statement if appropriate.
一定要花1-2分钟在试卷上草草写下关键点。找出题目中的关键词，并将其与相关的教学大纲主题联系起来。对于6分的题目，目标是写出5-6个独立的科学要点，并按逻辑顺序排列。常见的结构是：陈述观察结果、给出原因、再提供第二个关联的观点，并在适当的情况下以总结性陈述结尾。
3. Structure for 'Describe' Questions | '描述'类题目的结构
When asked to describe a graph, use data values (e.g., 'the temperature increased from 20°C to 80°C in the first 3 minutes, then remained constant'). For a practical set-up, detail what you see in sequence. Avoid the word 'because' — if you start explaining, you are no longer describing. Use comparative language: 'steeper', 'plateau', 'higher than'. Always quote units.
当被要求描述图表时，使用具体数据（例如"温度在前3分钟从20°C上升到80°C，然后保持不变"）。对于实验装置，按顺序详细描述所看到的现象。避免使用"因为"——如果你开始解释，就不再是描述了。使用比较性语言："更陡峭"、"平台期"、"比...高"。一定要引用单位。
4. Structure for 'Explain' Questions | '解释'类题目的结构
Begin with the underlying scientific principle. For example, in explaining diffusion, state 'particles move from a region of higher concentration to a region of lower concentration down a concentration gradient'. Then connect this principle to the specific scenario using linking words: 'therefore', 'as a result', 'which leads to'. Every explanation must reference particles, energy, forces or other core concepts. Never write a description in an explain question.
从潜在的科学原理开始。例如，在解释扩散时，陈述"粒子从高浓度区域沿浓度梯度向低浓度区域移动"。然后使用连接词将该原理与具体情境联系起来："因此"、"结果"、"这导致"。每个解释都必须涉及粒子、能量、力或其他核心概念。绝不要在解释题中写描述性内容。
5. Using Scientific Terminology Accurately | 准确使用科学术语
Marks are awarded for precise language. In Biology, terms like 'active transport', 'phloem', 'synapse' must be used correctly. In Chemistry, refer to 'collision frequency', 'activation energy', 'catalyst'. In Physics, use 'potential difference', 'resultant force', 'electromagnetic induction'. Incorrect terms, such as 'sucked up' instead of 'drawn up by transpiration pull', will lose marks. Build a glossary of subject-specific vocabulary.
精确的语言可以得分。在生物学中，必须正确使用"主动运输"、"韧皮部"、"突触"等术语。在化学中，要提到"碰撞频率"、"活化能"、"催化剂"。在物理学中，使用"电势差"、"合力"、"电磁感应"。错误的术语，比如用"sucked up"代替"由蒸腾拉力拉升"，会丢分。建立学科专属词汇表。
6. Evaluating Experiments: The CORMS Framework | 实验评价：CORMS框架
Many 6-mark questions ask you to plan or evaluate an investigation. Use the CORMS framework for experimental design: Change (independent variable), Organism / Object (what is being tested, keep it constant if appropriate), Repeat (to calculate a mean and identify anomalies), Measure (dependent variable, how and with what instrument), Same (control variables to ensure a fair test). If evaluating an existing method, comment on each CORMS aspect.
许多6分题目要求你计划或评价一项调查。使用CORMS框架进行实验设计：C改变（自变量），O生物/对象（被测试对象，如适用保持恒定），R重复（计算平均值并识别异常值），M测量（因变量，如何测量及用什么仪器），S相同（控制变量以确保公平测试）。如果评价现有方法，要对每个CORMS方面进行评论。
7. Handling Data and Graphs | 数据处理与图表
If the 6-mark question includes a table or graph, you must describe the trend using data. Quote figures for one or two specific points: 'at 0.5 mol/dm³ the rate was 2.1 cm³/s, while at 1.0 mol/dm³ it doubled to 4.2 cm³/s'. When drawing your own graph, label axes with quantity and unit, use a sensible scale, and draw a smooth line of best fit. Circle and ignore anomalous points.
如果6分题中包含表格或图表，你必须用数据描述趋势。引用一两个具体数值："在0.5 mol/dm³时，速率为2.1 cm³/s，而在1.0 mol/dm³时翻倍到4.2 cm³/s"。当你自己绘制图表时，用物理量和单位标注坐标轴，使用合理的刻度，并画出平滑的最佳拟合线。圈出并忽略异常点。
8. Model Answer: Diffusion in Biology | 范文：生物学中的扩散
Question: 'Explain how oxygen moves from the alveoli into the blood in the lungs.' (6 marks)
问题："解释氧气如何从肺泡进入肺部的血液。"（6分）
Model answer: Oxygen molecules in the alveoli are at a high concentration because inhalation continuously brings fresh air into the lungs. The blood arriving at the capillaries surrounding the alveoli has a low oxygen concentration, as the oxygen has been used in respiration. This creates a steep concentration gradient. Oxygen diffuses from the area of high concentration in the alveoli to the area of low concentration in the blood plasma. The alveoli provide a large surface area and are one cell thick, which increases the rate of diffusion. Oxygen then enters red blood cells and combines with haemoglobin.
范文：肺泡中的氧分子处于高浓度，因为吸气不断将新鲜空气带入肺部。到达肺泡周围毛细血管的血液氧浓度低，因为氧气已在呼吸作用中被消耗。这就形成了一个陡峭的浓度梯度。氧气从肺泡中的高浓度区域扩散到血浆中的低浓度区域。肺泡提供了很大的表面积，且仅一个细胞厚，这提高了扩散速率。随后氧气进入红细胞并与血红蛋白结合。
9. Model Answer: Electrical Circuits in Physics | 范文：物理中的电路
Question: 'Explain what happens to the brightness of a lamp when an identical lamp is added in parallel to the circuit.' (6 marks)
问题："解释当一只相同的灯泡并联接入电路时，原灯泡的亮度会发生什么变化。"（6分）
Model answer: When a second identical lamp is added in parallel, the potential difference across each branch remains equal to the supply voltage. Therefore, the brightness of the first lamp does not change, as the current flowing through its filament stays the same. The total circuit resistance decreases, so the current drawn from the cell increases. The cell supplies more power, but the first lamp's own operating conditions remain unchanged. However, if the internal resistance of the cell is considered, the terminal voltage may drop slightly, causing a marginal decrease in brightness — but at IGCSE level, we assume an ideal cell with no internal resistance.
范文：当一只相同的灯泡并联接入时，每一支路两端的电势差保持与电源电压相等。因此，第一只灯泡的亮度不变，因为流经其灯丝的电流保持不变。电路总电阻减小，因此从电池中取用的电流增加。电池提供更多功率，但第一只灯泡自身的工作条件保持不变。然而，如果考虑电池的内阻，端电压可能会略微下降，导致亮度稍有降低——但在IGCSE级别，我们假设电池无内阻。
10. Model Answer: Rate of Reaction in Chemistry | 范文：化学反应速率
Question: 'Explain, in terms of particle collisions, why increasing the concentration of hydrochloric acid increases the rate of its reaction with magnesium ribbon.' (6 marks)
问题："从粒子碰撞的角度解释，为何增加盐酸的浓度会提高其与镁条的反应速率。"（6分）
reacting particles are closer together and the frequency of successful collisions between H⁺ ions and magnesium atoms increases. For a reaction to occur, particles must collide with energy equal to or greater than the activation energy. Because the total number of collisions per second rises, more collisions per second have sufficient energy, leading to a faster rate of hydrogen gas production. The equation is: 2HCl + Mg → MgCl₂ + H₂.
范文：盐酸中含有 H⁺ 离子。当盐酸浓度增加时，单位体积内的 H⁺ 离子更多。这意味着反应粒子更靠近，H⁺ 离子与镁原子之间成功碰撞的频率增加。要使反应发生，粒子碰撞的能量必须等于或大于活化能。由于每秒碰撞总数上升，每秒有更多碰撞具备足够的能量，导致氢气产生速率加快。化学方程式为：2HCl + Mg → MgCl₂ + H₂。
11. Common Mistakes to Avoid | 常见错误避免
Students often repeat the question in the answer without adding scientific content. Using vague phrases like 'it increases' without stating what increases loses marks. Omitting units, confusing 'describe' with 'explain', and writing everything in one block of text also penalise your answer. Another pitfall is copying data from the question without processing it — always select illustrative data and show you can interpret it. Finally, do not contradict yourself; check that your explanation aligns with the laws of science.
学生经常在答案中重复题目，而不添加科学内容。使用"它增加了"这样模糊的短语而不说明是什么在增加会丢分。遗漏单位、混淆"描述"与"解释"、以及把所有内容写成一大段文字也会扣分。另一个陷阱是直接照搬题目中的数据而不加处理——一定要选择有说明性的数据，并展示你能解读它。最后，不要自相矛盾；检查你的解释是否符合科学定律。
12. Putting It All Together: A Practice Template | 整合：练习模板
Before writing your final answer, mentally tick off: command word understood, key scientific terms listed, logical chain of points planned, data or examples to include, and a concluding sentence if needed. Use this template: (1) Definition or principle, (2) Application to the given situation, (3) Second linked concept, (4) Result / observation, (5) Numerical support or controlled variable mention. Practice with past papers using this structure under timed conditions.
在写下最终答案之前，在心里打勾：理解了命令词、列出了关键科学术语、规划了逻辑要点链、包含了数据或例子、以及必要的总结句。使用此模板：（1）定义或原理，（2）应用到给定情境，（3）第二个关联概念，（4）结果/观察，（5）数值支持或提及控制变量。在限时条件下，用此结构练习历年真题。
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