(共17张PPT)
Unit 5
Look into Science
Lesson 26
Keep the Candle Burning
Do you like doing science experiments
Why or why not
Lead in
Because experiments can enable us to explore the mysteries of nature.
Lead in
What experiment have they done before
Air Pressure test.
Review
Fill the glass jar with water.
Can you retell how to do the experiment
Cover the top with a piece of cardboard
Hold the jar over Danny’s head.
Turn the jar upside down
This is because air pressure pushes the cardboard onto the jar .
Lead in
2. What do we know from this experiment
1. What is the result of this experiment
The water stays in the jar .
What will happen if you put a jar upside down over a burning candle
Free Talk
a candle
a candle holder
a big glass jar
a shallow dish with water
a lighter or matches
What do you need to do the experiment
Reading tasks
□Fill the dish half full with water.
□Put the candle in the candle holder.
□Light the candle.
□Examine the water in the jar. What can you see
□Let the candle burn for two or three minutes.
□Put the candle holder on the dish.
□Carefully put the jar over the candle until the top of the jar rests on the dish.
Read and put the sentences into correct order.
1
4
3
2
7
6
5
Reading tasks
Watching
Reading tasks
What is happening
As the candle burns, it ______ the oxygen in the jar.
When the candle stops burning, it __________ all the oxygen in the air.
How far does the water rise The water fills about ________ of the jar.
Why Because about one fifth of the air ________________ oxygen.
uses
has used up
one fifth
is made up of
When the candle stops burning, it has used up all the oxygen in the air.
当蜡烛停止燃烧时,它已经耗光了空气中的氧气。
use up = run out of “用尽; 耗光”, 动副词短语。
He has used up all his energy.
他已筋疲力尽。
eat up “吃光”, 动副词短语。
孩子们吃光了苹果。
The children ate up the apples.
Language points
Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar.
一切动植物都是由细胞构成的。
All animals and plants are made up of cells.
Language points
因为空气的五分之一是由氧气组成的，所以水会上升到瓶子五分之一的位置。
one fifth “五分之一”
be made up of 意思是“用·······构成或组成的”
1. Desks and chairs ____ wood, while paper __ wood, too.
A. are made from； is made of
B. are made up of； is made of
C. are made into； are made out of
D. are made of； is made from
2. The house is made _______ wood and it is made ______ six rooms.
A. up of; of B. from; up of C. of; up of D. from; of
Exercises
材料
be made of 表示制成成品后，仍可看出原材料，保留原材料的质，制作过程仅发生物理变化；be made from 表示制成的东西完全失去了原材料的特性，在制作过程中发生化学变化，在成品中已无法辨认。
D
be made up of 由 ...... 组成 ( 一般指物体由几部分组成），
材料
组成部分
C
Circle the correct words to complete the sentences.
1.Don’t (use up /push up) all of the ink. Leave some for me.
2.The medical team (is made of / is made up of) five experienced doctors.
3.Please fill the hole (with /in) sand and water.
4.They didn’t realize their mistake (until /as) we told them.
5.My brother wasn’t (strong enough/enough strong) to lift the box.
Exercises
Let’s do the experiment together! Put the candle in the candle holder. Put the candle holder on the dish. Fill the dish half full with water. Light the candle with a________ or a lighter. What can you see The candle is burning. ____the candle burn for two or three minutes. Then carefully put the jar over it until the top of the jar rests on the dish. As the candle burns, it _____ the oxygen in the air.When the candle stops________, it has used up all the oxygen in the air. The water inside the jar _____ and fills about ________ of the jar. This is because about one fifth of the air is made up of oxygen.
Read the lesson and fill in the blanks.
burning
rises
one fifth
match
Let
uses
Reading tasks
Reading tasks
1.Can you show us how to do the experiment
1.What’s the result
What do we know from this experiment？
use up be made up of holder shallow lighter match examine oxygen
Put the candle in the candle holder.
Put the candle holder on the dish.
Fill the dish half full with water.
Light the candle.Let the candle burn for two or three minutes.
Carefully put the jar over the candle until the top of the jar rests on the dish.
Examine the water in the jar. What can you see
Summary
