TOEFL Junior · Unit 8 · B1
Unit 8 · 科学 Science
本单元语法主线：第一类条件句。题型覆盖听力理解（校园对话/通知/讲座）、语言形式与含义（语法词汇四选一）、阅读理解（课文/广告/信件）。学完后建议进入 深化页：第一类条件句。
01 主题语篇 · Reading & Listening
In science class, we are learning about plants. Our teacher, Dr. Brown, asked us to do an experiment. If you put a plant in a dark room, it will not grow well, she said. Plants need sunlight to make food. If you water them too little, they will die. But if you water them too much, their roots will rot. We divided our class into three groups. Group A will put a bean plant by the window. Group B will put it in a closet. Group C will put it outside. If the experiment works, we will see the difference in two weeks. We will measure the height every day. If the plant in the closet dies, we will know that light is necessary. Dr. Brown told us that if we do not record the data carefully, our experiment will be useless. Science is not just about doing — it is about observing and recording. We will present our results next Friday.
科学课上我们在学植物。老师 Brown 博士让我们做一个实验。如果你把植物放在暗室里，它长不好，她说。植物需要阳光来制造养分。如果水浇太少，它们会死。但如果水浇太多，根会烂。我们班分成三组。A 组把豆苗放窗边。B 组放壁橱里。C 组放室外。如果实验成功，两周后我们就能看到差别。我们每天量高度。如果壁橱里的植物死了，我们就知道光是必需的。Brown 博士告诉我们，如果不仔细记录数据，实验就没用。科学不只是做——它是观察和记录。下周五我们会展示结果。
核心词块：experiment, plant, sunlight, root, water, bean, closet, measure, data, observe
02 词汇延展 · Word Expansion
科学方法
experiment, hypothesis, observation, data, evidence, result, conclusion, measure
hypothesis 假设
生物植物
plant, root, leaf, stem, seed, sunlight, water, grow, die, rot
root 根；stem 茎
学科词汇
science, biology, chemistry, physics, lab, microscope, sample
lab = laboratory
条件句标志
if, when, unless, as soon as, in case, provided that
if 从句用现在时，主句 will
学术动词
measure, record, observe, present, divide, compare, prove
record the data 记录数据
03 语法延展 · Grammar (B1 爬坡)
If + present, will + 原形
真实未来条件
If you water it too little, it will die.
unless = if not
除非
Unless you water it, it will die.
when/as soon as
一…就
When the experiment ends, we will present results.
否定
If + don't/doesn't, won't
If you don't record data, the experiment will be useless.
⚠ 易错陷阱
- ① 主将从现： if 从句用一般现在表将来，主句用 will。✗ If it will rain, I will stay. → ✓ If it rains, I will stay.
- ② 逗号位置： If 从句在前加逗号（If it rains, I will stay.）；主句在前不加逗号（I will stay if it rains.）。
- ③ unless = if...not： Unless you hurry, you will be late. = If you don't hurry, you will be late.
- 考试怎么考： If you ___ (not water) the plant, it will die. → don't water。
04 功能句型 · Functional Patterns
口语 · 说假设
What will you do if it rains tomorrow?
If it rains, I will stay at home and read a book.
If it rains, I will stay at home and read a book.
If + present, will... 是 B1 口语标配。
写作 · 实验报告
If we put the plant in a dark room, it will not grow. We will measure the height every day.
实验报告用第一类条件句预测结果。
听力 · 老师指令
If you do not finish the experiment today, you will stay after class. If you finish early, you may leave.
老师指令里 if 条件句高频。
05 考点自测 · Self Check
1（填空）：
If it ___ (rain), we will stay at home.
查看答案
rains（if 从句一般现在，it 三单）
2（选择）：
If you study hard, you ___ the exam. A. pass B. will pass C. passed
查看答案
B（主句 will + 原形）
3（填空）：
___ you do not hurry, you will be late. (If / Unless)
查看答案
If（如果你不快点）
4（改错）：
If it will rain, I will cancel the picnic.
查看答案
If it rains（if 从句用一般现在表将来）
5（易混）：
I will call you as soon as I ___ (arrive).
查看答案
arrive（as soon as 从句也用一般现在）
6（场景）：
用英语说如果周末晴天你会做什么（第一类条件句）。
查看答案
示范：If it is sunny this weekend, I will go to the park with my family.
7（听力）
If you ___ (not finish) today, you will stay after class. 填什么？
查看答案
don't finish（if 从句否定一般现在）
8（写作）：
写 3 句关于环保的第一类条件句（If...will...）。
查看答案
示范：If we recycle paper, we will save trees. If we do not protect the river, fish will die. If everyone helps, our town will become cleaner.
06 拓展阅读 · Extended Passage（听力原稿风格）
Our science teacher, Dr. Brown, told us about a famous experiment. If you put a candle in a jar and cover it, the flame will go out in a few seconds. Why? Fire needs oxygen. When the candle uses up the oxygen in the jar, the flame dies. We tried it in class. We put a short candle in a plate of water. We lit it and covered it with a glass. Within seconds, the flame went out. Then something amazing happened: the water rose into the glass! The water rose because the air inside the glass had less oxygen, so the outside air pressure pushed the water up. If we use a taller candle, the water will rise even higher. Dr. Brown told us to record our observations carefully. If we do not write down what we see, our experiment will be useless. Science is about asking why and testing ideas.
科学老师 Brown 博士给我们讲了一个著名实验。如果你把蜡烛放进罐子里盖上，火焰几秒就会灭。为什么？火需要氧气。蜡烛用完罐子里的氧气，火焰就灭了。我们在课上试了。我们把短蜡烛放在装水的盘子里。点着后用玻璃杯盖上。几秒内火焰灭了。然后神奇的事发生了：水涌进杯子里！水上升是因为杯里氧气变少，外部气压把水压上去。如果用更高的蜡烛，水会升得更高。Brown 博士让我们仔细记录观察。如果不写下所见，实验就没用。科学就是问为什么并验证想法。
07 可直接套用句型（10 句）
- If you put a candle in a jar, the flame will go out.
- Fire needs oxygen to burn.
- When the candle uses up the oxygen, the flame dies.
- We lit it and covered it with a glass.
- The water rose into the glass.
- If we use a taller candle, the water will rise higher.
- If we do not write down what we see, the experiment will be useless.
- Science is about asking why and testing ideas.
- If you heat ice, it melts.
- What will happen if you water a plant too much?
08 加练 6 题（含答案）
9（填空）
If it ___ (rain), we will stay home.
查看答案
rains
10（选择）
If you study hard, you ___ the exam. A. pass B. will pass C. passed
查看答案
B
11（填空）
___ you do not hurry, you will be late.
查看答案
If
12（改错）
If it will rain, I will cancel the picnic.
查看答案
If it rains（if 从句一般现在）
13（场景）
用第一类条件句写一句如果周末晴天你会做什么。
查看答案
示范：If it is sunny, I will go to the park.
14（听力）
If we ___ (not write) it down, the experiment will be useless.
查看答案
do not write
09 听力原稿精听（Listening Script）
M: Hey, are you going to the school fair this Saturday?
W: I am not sure. I have a lot of homework this week.
M: But the fair only happens once a year. There will be games, food, and a concert in the afternoon.
W: Really? What time does it start?
M: It starts at ten in the morning. The concert begins at three.
W: How much is the ticket?
M: It is five dollars for students, and eight for adults. Half price if you bring a food donation.
W: That sounds like a good deal. I will ask my mom. Maybe I can finish my homework on Friday night.
M: Great! Let me know. I will save you a ticket.
W: Thanks. See you on Saturday, hopefully.
M: See you!
男：嘿，这周六你去学校游园会吗？
女：不确定。我这周作业很多。
男：但游园会一年才一次。有游戏、食物，下午还有音乐会。
女：真的？几点开始？
男：上午十点开始。音乐会三点开始。
女：票多少钱？
男：学生五美元，成人八美元。带食物捐赠半价。
女：听起来挺值。我问问我妈。也许我周五晚上能写完作业。
男：好！告诉我。我给你留张票。
女：谢谢。周六见，希望能去。
男：再见！
精听要点：抓时间（ten / three）、价格（five / eight / half price）、条件（if you bring / if you finish）。小托福听力题常考"他/她最后决定去不去"——听最后两句。
10 词汇例句扩展（每词配一句）
academic
The new library has more academic books than last year.
academic adj. 学术的
assignment
Our English teacher gave us a writing assignment.
assignment n. 作业
schedule
Check the schedule to see when the bus leaves.
schedule n. 时间表
opportunity
This trip is a great opportunity to practice English.
opportunity n. 机会
experience
Working on the farm was an unforgettable experience.
experience n. 经历；经验
improve
Reading every day will improve your vocabulary.
improve v. 提高
challenge
Learning a new language is a big challenge.
challenge n. 挑战
achieve
If you work hard, you will achieve your goal.
achieve v. 实现
11 写作范文（Email / Notice）
Dear classmates,
We are going to have a class party next Friday after school. It will be in Room 301. We will have snacks, music, and games. Please bring one dish to share. If you cannot come, please tell me by Wednesday.
We also need three volunteers to help clean the room after the party. If you are interested, please write to me.
I hope to see everyone there!
Best,
Linda
亲爱的同学们：
下周五放学后我们要办班级派对，在 301 教室。有零食、音乐和游戏。请带一道菜分享。如果不能来，请周三前告诉我。
我们还需要三名志愿者派对后帮忙打扫。有兴趣请写信给我。
希望大家都来！
Linda 敬上
小托福写作常考"写邮件通知某事"。结构：开头点明目的 → 时间地点活动 → 要求/邀请 → 结尾。用一般现在时通知安排，用 will 说将要发生的事。
12 阅读广告/信件类真题风格
SUMMER CAMP 2026
Where: Green Lake Park, 20 km from the city center
When: July 10 – July 24 (two weeks)
Who: Students aged 11–15
Activities: swimming, hiking, arts and crafts, team games, movie nights
Price: $250 per student (meals and bus included)
Sign up: before June 30 at the school office. Spaces are limited to 40 students.
For more information, ask Mr. Brown in Room 205.
Where: Green Lake Park, 20 km from the city center
When: July 10 – July 24 (two weeks)
Who: Students aged 11–15
Activities: swimming, hiking, arts and crafts, team games, movie nights
Price: $250 per student (meals and bus included)
Sign up: before June 30 at the school office. Spaces are limited to 40 students.
For more information, ask Mr. Brown in Room 205.
2026 夏令营
地点：绿湖公园，距市中心 20 公里
时间：7 月 10 日 – 7 月 24 日（两周）
对象：11–15 岁学生
活动：游泳、徒步、手工、团队游戏、电影之夜
费用：每人 250 美元（含餐食和大巴）
报名：6 月 30 日前到教务处。名额限 40 人。
详情问 205 室 Brown 老师。
地点：绿湖公园，距市中心 20 公里
时间：7 月 10 日 – 7 月 24 日（两周）
对象：11–15 岁学生
活动：游泳、徒步、手工、团队游戏、电影之夜
费用：每人 250 美元（含餐食和大巴）
报名：6 月 30 日前到教务处。名额限 40 人。
详情问 205 室 Brown 老师。
阅读理解题示例：Q: How long is the camp? A: Two weeks. Q: What is the price? A: $250. Q: Where do you sign up? A: At the school office. 小托福阅读广告题就考这种细节定位。
13 小托福题型答题技巧（4 条）
📌 应试策略
- 听力：听前先读选项，猜话题。听第二个人的回答，往往答案就在那里。
- 语言形式：先找时间标志词（yesterday / every day / already），定时态再选变形。
- 阅读：先读题，带着问题回原文定位。广告/通知类直接找数字和地点。
- 时间管理：不会的题先跳过，做完有时间再回来。别在一道题上卡 5 分钟。
14 单元小结与下一步
✅ 学完本单元你应该能：
- 听懂校园对话中关于时间、地点、价格的关键信息。
- 在四选一语法题中正确选择动词时态/变形。
- 读懂广告、通知、简短信件并提取细节。
- 用本单元句型写 3–5 句连贯的英文邮件或段落。
下一步：进入对应 知识深化页（左侧导航或文末链接），把语法点的规则、变形、易错点彻底吃透；然后回到本页重做题，直到全部答对。12 单元按 A2→B2 顺序推进，不要跳级。
15 本单元高频词自测（10 词中译英）
- 闹钟响了。 → The bell ___.
- 我走路上学。 → I ___ to school.
- 她正在吃饭。 → She ___ right now.
- 我们去年去了北京。 → We ___ to Beijing last year.
- 这是我见过最好的电影。 → It is the ___ film I have ever seen.
- 明天会下雨。 → It ___ rain tomorrow.
- 我已经完成作业了。 → I ___ my homework already.
- 你应该多喝水。 → You ___ drink more water.
- 正在说话的女孩是我妹妹。 → The girl ___ is speaking is my sister.
- 如果明天下雨，我们就待在家。 → If it ___ tomorrow, we will stay home.
参考答案
1. rings 2. walk 3. is eating 4. went 5. best 6. will 7. have finished 8. should 9. who 10. rains