课件46张PPT。 Look into Science Unit 5 Let’s Do an Experiment ! Lesson 25 课文呈现知识讲解…………Lesson 25 Let’s Do an Experiment! 课堂导入课文1课堂小结课后作业…词汇
听写课堂练习 同学们，上一课学习的单词你们都掌握了吗？现在大家来检验一下，点击下面的音频开始听写吧！Do you like doing experiments ? Why?THINK ABOUT IT·What kinds of experiments have you done in
science class?
·If you hold a jar that is filled with water upside
down，what will happen?
Danny，Jenny and Brian are in the lab.Brian：Let’s do an experiment?. I fill a jar with
water. I cover the top with a piece of cardboard
and hold it there. Then I turn the jar upside down? and take my hand off? the cardboard. Can you guess
what will happen?
Danny：I think the floor will get? wet. We should do this
experiment outside，Brian.
Jenny：I think the cardboard will hold the water.
Danny：I don’t think so.
Jenny：You think the water will pour out，Danny. I think
the water will stay in the jar. Let’s test which theory
is correct.Brian：Good idea，Jenny. That’s called? the
scientific? method.
Jenny：I am so sure of? my theory that Brian can do the
experiment over? your head and I know you won’t
get wet.
Danny：Well，let’s try it!
Brian：Are you ready，Danny?
Danny：No! Wait! (He puts on?a raincoat and sits down.)
Now I think I’m ready.
Jenny：Brian，take your hand off the cardboard.Danny：No!
(Danny closes his eyes tightly，and Brian takes his
hand off the cardboard. The water stays in the jar.)
Jenny：See，Danny!
Danny：How is that possible?
Brian：The force of the air keeps the water
in the jar. It is strong enough to hold the water.
Danny：Wow!
Brian：So what have we discovered ？1011Jenny：We have discovered that the air pressure
helps the cardboard hold the water in the jar.
Brian：Right. What do you conclude，Danny?
Danny：I conclude that air is stronger than I
thought. experiment /?k'sper?m?nt/ n.实验；试验 eg：Many people are against doing experiments
on animals. 许多人不赞成在动物身上做实验。知识点1考向一“做实验”可用do/make/carry out an
experiment表达。eg：Mr. Black is doing/making/carrying out an
experiment in physics.
布莱克先生正在做一个物理实验。experiment v.做试验，进行实验，常和介词on，with连用。
eg：He is experimenting on frogs.
他正在青蛙身上做试验。 考向二 turn…upside down 把……翻转；倒过来 考向反义短语为：turn...right side up 把……正面朝上。
eg：Turn the box right side up, please.
请把这个盒子正面朝上放。知识点2eg：Can you turn the glass upside down?
你能把这个玻璃杯倒过来吗？ take…off… 把……从……拿开 拓展take off 脱掉，摘掉，(飞机)起飞
eg：Bill took off his glasses.
比尔摘掉了他的眼镜。
The plane will take off at 2：00 p．m.
飞机将在下午两点起飞。知识点3eg：Please take your hand off the food.
请把你的手从食物上拿开。典例 He ________ my wet coat and made me sit by
the fire.
A．went by B．ran out
C．took off D．turned up【点拨】考查动词短语辨析。采用逻辑推理法。go by(时
间)流逝；run out用完；take off脱掉，(飞机)起飞；turn
up调高(音量)，出现。句意为：他脱掉我湿漉漉的外
套，让我在火炉旁坐下。故选C。 C get /ɡet/v.收到；(使)达到；变得 考向一知识点4get作系动词，表示“变得”，后跟形容词作表语。
eg：The weather will get cool when autumn
comes.
当秋天到来的时候，天气会变得凉爽。 考向二get相关的短语：
get along/on with…与……和睦相处
get away 离开，走开
get back 返回
get down 下来，写下
get on 上车 get off 下车
get together 会面，聚集典例We should think more of others if we want to ________them.(重庆A)
A. get on well with B. hear of
C. get ready for D. hear from【点拨】考查动词短语辨析。采用逻辑推理法。get on well with 和……相处得很融洽；hear of 听说；get ready for 为……做准备；hear from 收到……的来信。句意：如果我们想和其他人相处得很融洽，我们就应该多为他们着想。结合语境，可知选A。 AThat’s called…那被叫做…… 考向知识点5此句是一般现在时的被动语态，That在这句话中充当主语，is called 构成被动语态结构。一般现在时的被动语态的构成为：be动词(am/is/are)＋动词的过去分词。
eg：More money is saved by using both sides of
paper.
通过使用纸的两面，更多的钱被节省下来了。典例—Claudia, are you going to Jeff's birthday
party on Saturday?
—Unless I________． (湖北黄冈)
A. will be invited B. am invited
C. was inviting D. invited【点拨】考查被动语态和时态。句意：——克劳迪娅，周六你打算去杰夫的生日聚会吗？——除非我被邀请。unless引导条件状语从句，当主句(此处已省略)描述将来发生的动作时，从句中用一般现在时表示将来的动作。 Bscientific/?sa??n't?f?k/adj.科学的 考向知识点6eg：This is a scientific instrument.
这是一件科学仪器。scientific还表示“细致严谨的”。
eg：We need to be more scientific about this
problem.
在这个问题上我们需要更为严谨一些。be sure of 确信 考向知识点7eg：I am sure of what he said. 我确信他所说的。与sure有关的结构 典例It is sure ________ tomorrow morning.
A．rain B．to rain
C．raining D．to be rained【点拨】考查be sure to do sth.“一定/必然会做某事”。
句意：明天早上肯定会下雨。故选B。 Bover/'??v?(r)/ prep.在……上方，穿越知识点8eg：There was a lamp hanging over the table.
有一盏灯吊在桌子上方。考向【易错点】辨析 above，over与on put on 穿上；戴上；上演 知识点9eg：He puts on his best clothes for the party.
为了聚会他穿上了他最好的衣服。
The play had been planned to put on
today，but it was put off because of the
bad weather.
这部戏剧计划今天上演，但是因为坏天
气推迟了。 考向与put有关的短语： 典例The little child ________ the toys and went for dinner. (浙江嘉兴)
A．put on B．put up
C．put off D．put away【点拨】put on穿上；put up张贴；put off推迟；put away
把……收起。根据句意“这个小孩把玩具收起来去吃晚
饭。”可知选D。 D force/f??s/ n.力量 v.迫使；强迫 知识点10eg：the force of nature 大自然的力量force作动词时，常用的句式为：force sb.to do sth.＝force sb.into doing sth.意为“强迫某人做某事”。
eg：They forced him to leave his country.
他们强迫他离开了他的国家。考向 discover/d?'sk?v?(r)/ v.发现，发觉 考向知识点eg：Who discovered Hawaii? 谁发现了夏威夷？辨析 find，discover与invent 11用图片表示为：discover 发现invent 发明1.Read the lesson and answer the questions.
1．Where does Danny think they should do the experiment?
2．What keeps the water in the jar?
3．Is Jenny sure of her theory？How do you know?
4．Why does Danny put on his raincoat?
5．What does Danny conclude?
Outside. The force of air. Yes, she is. She asks Brian to do the experiment over Danny’s head and she knows he won’t get wet. He is afraid that he will get wet. He concludes that air is stronger than he thought. Let's Do It !
2. Read the experiment. Put the sentences in the correct order.
□Put a piece of cardboard over the jar.
□The jar of water is upside down，but the water
stays inthe jar. This is because air pressure pushes
the cardboard onto the jar.
□Fill the glass jar with water.
□Turn the glass jar over quickly. Hold your hand on the
cardboard for a few seconds.
□Remove your hand from underneath the jar. What happens?
□There is more air outside the jar than inside，so there
is more air pressure outside than inside.251346Let's Do It !
3. Try to do the experiment in this lesson yourself.
Task tips：What happens when you use less water，
more water，wet cardboard，or different kinds and
sizes of jars?Let's Do It !
4. Listen and sing along.What Is Science?
What is science?
Can you explain?
Please make it easy for my brain.
It’s about making observations .
Why do onions make me cry?
Why do clouds go by?
What keeps the birds in the sky?
That’s just science.12Let's Do It !
It’s about matter—the universe.
Why does a car stay on the road?
Why is there green all over a toad?
Why can’t I carry a heavy load?
That’s just science. Let's Do It !make observations 观察知识点eg：While doing experiments，you must
make careful observations.
做实验时，你必须仔细观察。make observations还可意为“作评论”。
eg：Mr. Wang made some useful observations
on the Internet.
王老师在网上作了一些有用的评论。考向12 本节课主要学习了以下重点内容:
（1）重点单词：experiment，get, scientific,
over, force, discover等。
（2）重点短语：upside down，take off，be
sure of , put on等。
（3）重点句式：that’s called…一、根据句意及首字母或汉语提示补全单词
1．It’s the best ________ of working out the math problem.
2．I’m sure that the ________ of the air will keep the water
in the jar.
3．Can you help me ________ the mistake that you find?
4．Put on the________ (雨衣)for it's raining heavily.
5．Don't turn the cup ________ (上部)down.method cforce orrect raincoat upside 二、单项选择
6．Tom is covering the cup ________ a piece of paper.
A．for B．on
C．with D．in
7．I won’t force anybody ________ anything.
A．do B．does
C．to do D．Doing
8．(中考·成都)Mum wants to watch CCTV news.
Let’s________ the TV.
A．turn down B．turn on C．turn offCCB9．He ________ my wet boots and made me ________
by the fire.
A．took off; sitting B．took off; sit
C．put off; sit D．put off; sitting
10．(中考·成都) —Excuse me, do you know________？
—About five minutes’ walk.
A．where the hospital is
B．how far the hospital is
C．how I can get to the hospitalBB三、连词成句(注意词形变化)
11．got，the，boy，rainy，in，wet，the(.)
_________________________________________
12．red，with，the，is，basket，apples，fill，big(.)
_____________________________________________
13．his，brother，covered，hands，face，with，his，my(.)
_____________________________________________
14．five，am，she，sure，minutes，come，in，will，I(.)
____________________________________________
15．(中考·上海) doing, the students, in the lab, an
experiment, are(.)
____________________________________________The boy got wet in the rain. The basket is filled with big red apples. My brother covered his face with his hands. I am sure she will come in five minutes. The students are doing an experiment in the lab. 1.熟记本课时的词汇
2.完成本课时的课后作业
