冀教版九上英语 U5 Lesson 26 Keep the candle burning 课件(共35张PPT)

(共35张PPT)
Look into Science
Unit 5
Lesson 26
Keep the Candle Burning
You should learn the New words and expressions.
Read the text and learn to do and talk about the experiment.
May you love science!
shallow adj. 浅的
match n. 火柴,比赛
burn v. 燃烧
light v. 点燃
use up 用完
candleholder n. 蜡烛座
Expressions
use up 用完；用尽
one fifth 五分之一
be made up of ... 由.......组成
Today we are going to look into science
again and learn to do another experiment.
What experiment will we do
Keep the Candle Burning!
1. What do we need
a candle
a big glass jar
a candleholder
a shallow dish with water
matches
a match
2. How do we do the experiment
3. What is happening
Read carefully and answer the questions:
What’s the title(题目) of the reading
2. What do you need to do the experiment
●a candle
● a candleholder
● a big glass jar
● a shallow dish with water
● matches
Keep the Candle Burning!
1. Put the candle in the candleholder.
2. Put the candleholder in he dish.
3. Fill the dish half full of water.
4. light the candle.
5. let the candle burn for two or three minutes.
6. careful put the jar over the candle until the top of the jar rests on the dish.
7. look at the water in the jar. What observation can you make
As the candle burns, it uses up oxygen in the air. When the candle stops burning, it has used up all the oxygen in the jar. The water inside the jar then rises. How far did the water rise There is about one-fifth oxygen in the air, so the water rises and fills about one-fifth of the jar.
Read the text again and finish
“Let do it”Ex. 1，2
1) 分数由分子及分母两部分构成。用英语表达时，分子用基数词，分母用序数词。
2) 若分子为1，则分母的序数词为单数形式，若分子大于1，则分母的序数词用复数形式。
＝ one (a) half 或 one second (one-second)
= one (a)quarter 或 one-quarter
分数的英语表达
二分之一
三分之一
四分之一
四分之三
五分之二
十分之九
口 诀:
分子基，分母序。分子﹥1 ，分母加s 。
a/one half (one second)
one-third
one quarter
three-fourths three quarters
two-fifths
nine-tenths
Keep the candle burning! 让蜡烛燃烧！
keep…burning使……燃烧。keep sth. (sb.) doing, 使某物（某人）保持做某一动作。
Don’t keep the water falling. 不要再让水继续流了。
She kept me holding the far with my hand. 她让我一直用手握住瓶子。
The water inside the jar then rises. 这时瓶子里的水就会上升。
rise v. 上升，升起。这是一个不及物动词。
The sun rises in the east. 太阳在东方升起。
The river is rising after the heavy rain. 大雨后河水上涨。
注意比较：raise为及物动词，后跟宾语，“提高，升起”
Liu Fei raised her hand and asked a question. 刘非举手问了一个问题。
Please raise your hand and asked a question. 请抬起头来。
As the candle burns, it uses up oxygen in the air. 当蜡烛燃烧的时候，需要消耗空气中的氧气。
1) as在本文中的意义为“当……的时候”。是一个有着多重意义的词。
Please do it again as I did. 请像我做的那样再做一遍。（as像……一样）
As it is late, I have to leave now. 由于天太晚了，我得走了。（as由于，因为）
You will find the building as you reach the end of the street. 当你走到这条街那头，你就会看到那座大楼。（as当……时候）
2) use up用光，耗尽。表示完全，彻底。
He was hungry and ate up the bread. 他饿了，把面包全吃光了。（eat up吃光）
Jim used up his money to buy the computer. 吉姆为了买电脑花光了所有的钱。
Can an egg “swim”in the water
1. What do we need
Do an experiment：
First, _________________________.
put some salt into the glass
Then, _______________.
add some water
next, ______________________________.
mix the salt and the water together
Finally, ______________________.
put the egg into the glass
The egg can’t touch
the bottom of the
glass and it swims
in the water.
3. What is happening
4. Why
盐水的密度变大，鸡蛋的浮力大于重力。
There are lots of matchs in the small box.
Can you let my uncle laughing
You’re very ill, so you must stop to smoke.
Fill the dish half fill of water.
There is about one–five oxygen in the air.
There are about two–third students in
the classroom.
7. I used out my money. Can you lend me some
Correct the mistakes.
matches
laugh
smoking
full
one-fifth
two-thirds
up
用所给单词的正确形式填空。
You are very tired. You’d better stop
______ (have) a rest.
2. What do you use to make a candle
_____ (burn)
3. You should put the jar over the candle
________ (careful).
4. What ____________ (observe) can you
make
to have
burn
carefully
observation(s)
5. Please cut the apple into ______ (half).
6. He _________ (light) a candle and the room was bright.
7. ______ (two), ask the students to guess
what will happen.
8. He kept the candle _______ (burn) for
two hours.
9. It’s time ______ (play) basketball.
10. What about _____ (go) for a walk
halves
lighted / lit
Second
burning
to play
going