Unit 5 Lesson 26 Keep the Candle Burning课件 冀教版英语九年级全册（21张PPT含音频）

(共21张PPT)
Unit 5 Lesson 26
We will learn
The new words:
holder, shallow, lighter, match, examine, oxygen
Important and difficult points:
①Let the candle burn for two or three minutes.
②When the candle stops burning, it has used up all the oxygen in the air.
③How far does it rise
④Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar.
Do you like doing science experiments
Why or why not
Lead in
Think about it
What will happen if you put a jar upside down over a burning candle
a candle
What do we need to
do the experiment
a candle holder
lighter
light (lit, lighted / lit, lighted)
点燃，使燃烧
burn (burned, burnt/ burned, burnt)
燃烧
a match
matches
a big glass jar
a shallow dish with water
Read and answer the questions.
1. How much water should we fill the dish
2. How long should we let the candle burn
3. Where should we put the jar
Half full of the dish.
Two or three minutes.
Put it over the candle until the top of the jar rests on the dish.
Listen
Part : Listen and answer the question.
What is happening
The water inside the jar rises.
Read and answer the questions.
1. Why does the water rise
2. How far does the water rise
When the candle stops burning, it has used up all the oxygen in the jar. So the air pressure outside the jar is stronger than that in the jar, and the force of the air outside makes the water inside rise.
One fifth of the jar.
Part :
Language points
1.Science is so interesting!
so为副词,“这样,如此”,用于修饰形容词或副词的原级,表示程度。常见用法如下:
(1)“so+形容词+a/an+单数名词”
“such a/an+形容词+单数名词”。
(2)so后可接many,much,few和little来表示名词的数量。
(3)so…that…“如此…以至于……”
2.Light the candle.
light（lighted/lit,lighted/lit） v.“点燃”
light up“点(烟),照亮”（代词放中间）
(1)light n.“灯,光”。
(2)light adj.“轻的,浅的”。
3.Carefully put the jar over the candle until the pf the jar rests on the dish.
until “直到”
①“直到......为止”，用于肯定句，表示主句动作一直持续到从句动作发生或状态出现时为止，主句谓语动词必须是延续性动词。
He lived with his parents until he got married.
②not...until... 直到......才......
The children won’t come home until it is dark.
4.When the candle stops burning,it has used up all the oxygen in the air.
use up=run out of…“用完,用光”(代词放中间)
eg:Lily has used up all her money.
I need some water.Don’t use it up.
5.The water inside the jar rises.
rise(rose,risen) V.“升起,上升”多用于表示日月星辰的升起、河水或物价上涨等方面。
eg:The sun rises and bathes the earth.
The river is rising after the rain.
The price of food has risen these days.
6.Because about one fifth of the air is made up of oxygen,the water rises and fills about one fifth of the jar.
◆one fifth“五分之一”
分数的表达：分子基，分母序。分子大于1，分母+S
【注意】　分数后面跟of短语作主语时,谓语动词的单复数由of后面的名词的单复数决定。
Homework
1.请根据课文内容, 以 “An Interesting Experiment”为题写一篇小作文。
2.Preview Unit 5-Lesson 27.
Bye-bye!