Unit 3 The world of science 写作精讲-2026-2027学年高中英语必修第三册单元话题写作精讲（外研版）

高中外研版·必修第三册 Unit3 The world of science写作精讲 Writing an experiment report(写实验报告) Unit3 The world of science·写作精讲：Writing an experiment report(写实验报告) 写作在务：Writing an experiment report(写实验报告) 审题 1 话题：描述一次科学实验的过程与结果，包括实验目的、材料、步骤、观察结果和结论。 2 体裁：说明性应用文（实验报告），通常以书面形式呈现。 3人称：以第-人称复数we为主（如We conducted.),也可用第三人称被动语态（如 The experiment was carried out...). 4 时态： >实验目的、材料、步骤：一般过去时（如Ne used,Ne placed) ,普逼事实或结论：一般现在时（如The result shows that.…) 5 字数要求：高考标准100-120词。 6 核心要点： >明确实验目的(Purpose) >列出所需材料(Materials) >按顺序描述实验步骤(Procedure) ,记录观察结果(Results) >得出结论或分析(Conclusion) 二、 文章结构（三段式展开 1 开头段：点明实验目的和背景。 In order to test how salt affects the floating of eggs,we conducted an experiment. 2 主体段： >简述材料（一句话概括即可） >按顺序描述步骤（使用frst,then,next,finally等连接词） >汇报观察结果（如"The egg sank in fresh water but floated in salt water'") 3 结尾段： >总结实验结论（直接回答实验目的） ,可加一句反思或应用（如"This proves that density of water increases with salt.") 三、核心词句 1.核心词汇 词汇 释义 experiment n.实验 purpose/aim n.目的 material n.材料 procedure n.步骤 observe /observation V.观察；n.观察结果 result n.结果 conclusion n.结论 hypothesis n.假设 variable n.变量 data n.数据 2.常用短语 短语 释义 carry out conduct an experiment 进行实验 短语 释义 set up the equipment 安装设备 record the data 记录数据 compare...with .. 将与…比较 turn out 结果是 draw a conclusion 得出结论 in order to do sth. 为了做某事 as is shown in the table 如表所示 3.基础造句 1The purpose of this experiment is to find out whether salt affects the density of water. 这个实验的目的是探究盐是否影响水的密度。 2 First,we filled a beaker with 200 ml of water. 首先，我们用200毫升水装满烧杯。 3 Then,we added 10 grams of salt and stirred it until it dissolved. 然后，我们加入10克盐并搅拌直到它溶解。 4We observed that the egg floated in the salt water but sank in fresh water. 我们观察到鸡蛋在盐水中漂浮，在淡水中下沉。 The result shows that salt water has a higher density than fresh water. 结果表明盐水密度比淡水大。 四、好词好句（高级加分句型 高级词汇替换 普通 do an experimentconduct/carry out an experiment 普通 showdemonstrate indicate/reveal 普通】 find out→ investigate/determine 普通 at firstto begin with initially 加分句型 1被动语态用于步骤描述（客观严谨） The beaker was filled with 200ml of water,and then 10g of salt was added. 烧杯里装入了200毫升水，然后加入了10克盐。 2定语从句补充结果 The egg,which had sunk in fresh water,began to rise slowly after salt was added. 原本在淡水中下沉的鸡蛋，在加盐后开始慢慢上升。 3现在分词短语作状语 Adding salt gradually,we noticed that the egg floated to the surface. 我们逐渐加盐，注意到鸡蛋浮到了水面。 4结论句使用强调结构/倒装 Only when the salt concentration reached a certain level did the egg start to float. 只有当盐浓度达到一定程度时，鸡蛋扌开始漂浮。 5结果对比句型 In contrast to the fresh water group,the egg in salt water floated. 与淡水组相此，盐水中的鸡蛋浮了起来。 五、写作模板 (100-120词) Title: Purpose:The purpose of this experiment was to Materials:We used Procedure: First, Then, Next, Finally, Results:We observed that Conclusion:The experiment demonstrates that Therefore,we can conclude that 参考翻译： 标题： 目的：这个实验的目的是为了 材料：我们使用了 步骤： 首先， 。然后， _。接下来， 。最后， 结果：我们观察到 结论：实验表明 因此，我们可以得出结论： 六、作文仿(120词左右) 仿写题目：做一次关于“盐对鸡蛋浮力影响”的实验，写一篇实验报告。 Title:The Effect of Salt on Egg's Buoyancy Purpose:The purpose of this experiment was to find out whether adding salt to water could make an egg float. Materials:We used a fresh egg,a glass beaker,200 ml of water,and 20 grams of salt. Procedure: First,we poured 200 ml of water into the beaker and gently placed the egg into it. The egg sank immediately.Then,we added 5 grams of salt and stirred it until dissolved.The egg remained at the bottom.Next,we added another 5 grams of salt.When the salt concentration reached about 15 grams,the egg began to rise slowly.Finally,after adding all 20 grams of salt,the egg floated near the surface. Results:We observed that the egg sank in fresh water but floated when enough salt was added. Conclusion:The experiment demonstrates that salt water has higher density than fresh water,which increases buoyancy.Therefore,we can conclude that salt concentration determines whether an egg floats or sinks. 参考译文： 标题：盐对鸡蛋浮力的影响 目的：本实验旨在探究向水中加盐是否能使鸡蛋浮起来。 材料：我们使用了一个鲜鸡蛋、一个玻璃烧杯、200毫升水和20克盐。 步骤： 首先，我们将200毫升水倒入烧杯，轻轻放入鸡蛋，鸡蛋立刻沉了下去。然后，我们加入5克盐并搅拌至溶 解，鸡蛋仍在底部。接着，我们又加入5克盐。当盐浓度达到约15克时，鸡蛋开始缓慢上升。最后，加入全部 20克盐后，鸡蛋浮到水面附近。 结果：我们观察到鸡蛋在淡水中下沉，但加入足够的盐后便浮了起来。 结论：实验表明盐水密度大于淡水，因此浮力增大。因此，我们可以得出结论：盐浓度决定了鸡蛋是浮还是 沉。 拓展范文背诵积累 范文一：建议朋友改善睡眠质量 Dear Tom, I am sorry to hear that you are troubled by poor sleep recently.I am writing to offer you some effective suggestions. 1.First of all,it is a good idea to set a fixed bedtime every day,because it helps regulate your body clock and makes it easier to fall asleep. 2.Besides,you should avoid using smartphones or tablets an hour before bed, which can reduce blue light and calm your brain. 3.Last but not least,I strongly advise you to listen to soft music or do light stretching before sleeping,as it is beneficial to relaxing your body and mind. I hope my advice will work for you.I'm sure you will enjoy better sleep soon. Yours sincerely, Jack 范文二：建议同学提高数学成绩 Dear Li Hua, I'm glad to receive your letter asking for advice on improving math scores.I'd like to share some practical tips with you. 1.First of all,it is a good idea to review basic formulas and concepts every day, because it helps you build a solid foundation and avoid careless mistakes. 2.Besides,you should practice at least three math problems from past exams each week,which can train your thinking and speed up problem-solving 3.Last but not least,I strongly advise you to ask your teacher for help when you get stuck,as it is beneficial to clearing up doubts and deepening understanding. I hope my advice will be helpful.I'm looking forward to your progress. Yours sincerely, Cindy