(共22张PPT)
Unit 5 Look into Science
Lesson 26 Keep the Candle Burning
1. To understand the meaning and usage of the new words and expressions.
2. To learn to do the experiment by yourself.
3. To learn the scientific method and enjoy science.
Learning objectives
Do you like doing science experiments
Free Talk
Why or why not
What will happen if you put a jar upside down over a burning candle
Science is so interesting!
I’m sure you’ll like this experiment!
Free Talk
What do you need
·a candle
·a candle holder
·a big glass jar
·a shallow dish
·some water
·a lighter or matches
Free Talk
The candle holder is “holding” the candle!
New words and expressions.
holder [ h ld (r)]
shallow [ l ] lighter [ la t (r)] match [m t ]
examine [ ɡ z m n]
oxygen [ ks d n]
n. 支托物;持有者
adj. 浅的
n. 打火机;点火器
n. 火柴
v. 相称;相配
v. 检查
n. 氧气
□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.
Listen to the tape and put the sentences into correct order.
1
4
3
2
7
6
5
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.
1
burning
rises
one fifth
match
Let
uses
1.Fill the dish half full with water.倒半碟水。
half full with water 是形容词短语, 在句中作状语, 表伴随状态。
Language Points
half 形容词, 意为“一半的”
half an/a ＋名词, 意为“半个……”
eg：half an hour 半个小时
half of… 意为“一半的……”, 后接名词时, 一般要在名词前加the、形容词性物主代词或指示代词等。此结构作主语时谓语动词和of后的名词保持一致。
eg：Half of the books are about science. 一半的书是关于科学的。
Half of the bag is empty. 袋子空了一半。
2.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。
stops burning “停止燃烧” stop doing sth. “停止正在做的事”
eg：Stop talking, please.请停止说话。
stop to do sth. “停下(正在做的事)去做另一件事”
eg：They stop to talk. 他们停下来去说话。
stop sb.(from) doing sth. “阻止某人做某事”
eg：We stop the boys (from) climbing the tree. 我们阻止男孩们爬树。
use up = run out of “用尽; 耗光”, 动副词短语。
eg：He has used up all his energy. 他已筋疲力尽。
[拓展] 与 “up”有关的短语：
take up 开始从事;占据;接受 The computer takes up so much room.电脑占据了太多空间。
cut up 切碎 Cut up the vegetable.把蔬菜切碎。
give up 放弃 Don’t give up and you will succeed.
别放弃, 你会成功的。
3. How far does the water rise 水面上升了多少？
far 在本句中表示“深（的程度）”
eg：They walked far into the forest. 他们走进森林深处。
Don't work far into the night. 不要工作到深夜。
how far 用于询问两地间的距离,答语也要用表示距离的句子
eg：—How far is it from your home to school 从你家到学校有多远？
—It is about 5 minutes’ walk.大约步行5分钟的路程。
4. Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar. 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。
be made up of 意思是“用·······构成或组成的”
eg: I want my staff to be made up of excellent workers.我希望我的员工都非常出色。
All animals and plants are made up of cells. 一切动植物都是由细胞构成的。
one fifth “五分之一” 分数的表达形式：分子用基数词, 分母用序数词, 当分子大于1时, 分母加 “s”
[拓展] 分数作主语时, 谓语动词的单复数形式取决于其后的名词。
eg：Two thirds of the students are boys in our class.
我们班三分之二的学生是男孩。
Two thirds of the apple is rotten.
这个苹果的三分之二烂了。
SCIENCE？THAT’S INTERESTING!
PROJECT
Read about the experiment in this lesson. With a group of classmates, practice the experiment. Do your experiment in front of the class. Don’t forget the following things：
First, describe your experiment.
Second, ask the class what they think will happen.
Third, do the experiment.
Finally, ask the class if the result is what they expected.
Do the experiment and describe the steps in English.
Action
Circle the correct words to complete the sentences.
2
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.
What did we learn
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
根据句意及首字母提示完成句子.
1．Our salt has _______ (用完), please buy some.
2．The water here is s______, not deep.
3．It's dangerous for children to play with ________ (火柴).
4．There is little ______ (氧气) at the top of the mountains.
5．_______(检查) your paper carefully before hand it in.
used up
hallow
matches
oxygen
Examine
1. You look tired. You’d better ________ a good rest.
A．stop to have B．stop having
C．to stop to have D．to stop having
2. —________is it from the village to your farm
— About 10 minutes’ walk.
A．How often B．How soon
C．How long D．How far
3. About ________ of the students like keeping diaries in English in our class.
A．two fifth B．two fifths C．second five D．two five
单项选择
GOOD JOB
