冀教版英语九年级上册Unit 5 Look into Science Lesson 25 Let's Do an Experiment!课件(共24张PPT)

(共24张PPT)
Lesson 25
Let’s Do an Experiment!
Leading in
What experiments have you done
Maybe we have done……
Leading in
Do experiments in science class.
Leading in
Let’s do an experiment.
a piece of cardboard
a jar some water
We need
Leading in
fill the jar with water
cover the top with a piece of cardboard
turn the jar upside down
Take hand off the cardboard
Leading in
What will happen
the floor will get wet
the water will pour out
Leading in
We conclude
the air is strong to hold the water in the jar
Leading in
Learning aims
1. The new words: experiment, jar, upside,
pour, correct, scientific, method, raincoat,
force, pressure, conclude
2.To understand the theory of the experiment.
3.To learn actively.
Words and
Expressions
experiment
jar
upside
pour
correct
scientific
n. 实验；试验
n. 广口瓶；罐子
n. 上部；上边
v. 倒出；倾倒
adj. 正确的；恰当的
adj. 科学的
Words and
Expressions
method
raincoat
force
pressure
conclude
n. 方法；办法
n. 雨衣
n. 力量
v. 迫使；强迫
n. 压力；压强；挤压
v. 得出结论；推断出
Listen to the lesson and answer the following questions.
1.What’s Danny’s theory
2.What’s Jenny’s theory
3.What does Danny conclude
Danny thinks the floor will get wet.
Jenny thinks the water will stay in the jar.
Danny concludes that air is stronger than he thought.
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 the air.
He is afraid to get wet.
The air is stronger than he thought.
1
Yes, she is. She asks Brian to do the experiment over Danny’s head and she knows he won’t get wet.
Read and 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 in the jar .This is because air pressure pushes the cardboard onto the jar .
( )Fill the glass jar with water.
2
5
1
2
( ) Turn the glass jar over quickly .Hold your hand on the card 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 .
Read and put the sentences in the correct order.
3
4
6
2
原文呈现
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.
fill …with… 用…装满… He has filled his case with
many books.
cover…with… 用…盖住…I cover the top with a piece of cardboard.
upside down “向下翻转过来”.
You hold the book upside down. 你把书拿倒了。
right side up “正面朝上”
原文呈现
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.
be sure 表示肯定, 有把握,而be not sure 表示不确定
be sure/ be not sure 后可接句子，还可接代词、名词、
动名词或不定式。
常见用法： be sure of sb / doing sth , be sure to do sth
be sure that…
原文呈现
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
take...off...意为“把......从......拿开”
Please take your hand off the food.
take off “摘掉，脱掉；起飞”
When will the plane take off
原文呈现
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
Jenny: 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..
enough 的两种用法
1.enough 与修饰词的排队顺序:(1)作形容词时, 置于名
词前、后均可 (2)作副词时, 置于所修饰的形容词、副之后
2. enough to do sth. 常与too. . . to或so. . . that进行句型转换
Tom isn’t old enough to go to school.
→Tom is too young to go to school.
→Tom is so young that he can’t go to school.
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
3
1. He locked the door ________ (careful) before he left.
2. Let's ______ (finish) the work together now.
3. Can you guess what __________ (happen) in 100 years
4. What's another way of _______ (say) “autumn”
saying
I. 用所给单词的适当形式填空。
carefully
finish
will happen
Exercise
1. 我确信你是一个诚实的人。
I ______ ______ that you are an honest man.
2. 请用一块玻璃盖上那个杯子。
Please ______ the cup _____ a piece of glass.
3. 小心，否则你会弄湿的。
Be careful, or you'll ______ ______.
4. 把箱子倒过来，你会找到标签的。
______ the box _______ _______, then you'll find the label.
II. 根据所给汉语意思翻译下列句子。
am sure
cover with
get wet
Turn upside down
Exercise
Homework:
1. Preview the words and expressions in Lesson 26.
2. Finish the exercise of this lesson.
Thank you!