Lesson 25 Let’s Do an Experiment!教学设计一等奖

Lesson 25

Let’s Do an Experiment!

教学目标

1. Words and phrases 1experiment,jar,upside,pour,correct,scientific,method,raincoat,force,pressure,conclude;短语turn…upside down,pour out,scientific method,take…off。

2.掌握重点句型:①Then I turn the jar upside down and take my hand off the cardboard.②That’s called the scientific method.

3.能够运用所学知识介绍自己做实验的过程。

4.能够确定定语从句的先行词和关系词。

教学重难点

1.能够正确应用本课的重点词汇

experiment,jar,upside,pour,correct,scientific,method,raincoat,force,pressure,conclude;掌握短语turn…upside down,pour out,scientific method,take…off。

2.能够运用所学知识介绍自己做实验的过程。

3.能够确定定语从句的先行词和关系词。

教学准备

教师在课前设计教学PPT,准备录音机和磁带,多媒体等,广口瓶,纸板和水。

教学过程

StepⅠ.Lead in

Leading in

The teacher brings a jar,a cardboard and water to the class.Show them to the students and ask what experiments we can do with them.Let the students show them and explain the reasons to the students.

Let the students work in groups and discuss the experiments. StepⅡ.Presentation

The teacher shows the new words on PPT.Ask students to try to read these words.The students follow the teacher three times.Then give the students five minutes to remember the words.Let students spell and read them one by one. StepⅢ.Reading

1.Read the text aloud.

T:Boys and girls,it’s our reading time.Please read after the video and you should pay more attention to your pronunciation.

2.Careful reading.

(1)Give the students five minutes to read the text by themselves.

Read the lesson and answer the questions.

①Where does Danny think they should do the experiment?

②What keeps the water in the jar?

③Is Jenny sure of her theory?How do you know?

④Why does Danny put on his raincoat?

⑤What does Danny conclude?

(2)Read the experiment.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.

Turn the glass jar over quickly.Hold your hand on the cardboard 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.

3.Read the text and find out main phrases and sentences.

Main phrases:

·turn…upside down

·pour out

·scientific method

·take…off

Main sentences:

·I think the floor will get wet.

·We should do this experiment outside,Brian.

·That’s called the scientific method.

·I am so sure of my theory that Brian can do the experiment over your head and I know you won’t get wet.

·He puts on a raincoat and sits down.

·How is that possible?

·It is strong enough to hold the water.

·So what have we discovered?

·What do you conclude,Danny? Language points

1.Then I turn the jar upside down and take my hand off the cardboard.

◆turn…upside down意为“把……翻转/倒过来”,相当于turn over。upside down意为“正面朝下”。right side up意为“正面朝上”。

◆take…off…在本句中意为“使……离开/脱离……”或“把……从……拿开”。

【拓展】

take off意为“摘掉,(飞机)起飞,脱掉”。

2.I think the floor will get wet.

◆I think…意为“我认为……”,其后可接that引导的宾语从句。在使用时,应遵循“否主反从”的规律,即否定主句,反问从句。

◆get wet意为“变湿”。get在本句中为系动词,意为“变得…,后接形容词作表语。

3.We should do this experiment outside,Brian.

experiment为可数名词,意为“实验”。do experiments/do an experiment意为“做实验”。【拓展】

experiment作动词,意为“做实验,进行试验”。

4.You think the water will pour out,Danny.

pour out意为“倒出,使流出,涌出”。pour在本句中表示“涌流”。

【拓展】

pour…into…意为“把……倒进……”。

5.That’s called the scientific method.

◆be called意为“被叫作”,是被动语态。被动语态是由“be+及物动词的过去分词”构成,其中be动词可随句子时态的变化而变化。

◆scientific为形容词,意为“科学的”。scientist为可数名词,意为“科学家”,science为不可数名词,意为“自然科学”。

◆method为可数名词,意为“方法,办法”。

6.I am so sure of my theory that Brian can do the experiment over your head and I know you won’t get wet.

本句中的be sure of意为“对……有把握”。

7.He puts on a raincoat and sits down.

put on意为“穿上”,为“动词+副词”构成的短语,代词作其宾语必须放在动词和副词之间。

8.How is that possible?

possible为形容词,意为“可能的,合适的”,其反义词为impossible,意为“不可能的”,possibly为副词,意为“可能地”。

9.It is strong enough to hold the water.

“It is+形容词+enough to do sth.”意为“做某事是足够……的”,常用来表述某人或某物的能力或特征。在此句型中,当不定式的逻辑主语与句子的主语不相同时,常用for引出不定式的逻辑主语。该句型可以和too…to…及so…that…句型相互转换。

10.So what have we discovered?

discover为动词,意为“发现”,是指发现或找出某种自然界本来已存在,但以前未被人类发现或认识的事物。

【辨析】

find,find out,discover,invent

(1)find意为“找到,发现”,强调“找”的结果,也可指偶然发现、碰到,其后可接名词、复合结构或that从句。

(2)find out指“弄清楚,查明”。着重表示通过调查、分析、思考等得出结果。

(3)discover意为“发现”,指发现已存在但不为人所知的事物。

(4)invent意为“发明”,指发明原来不存在的东西。

11.What do you conclude,Danny?

conclude为动词,意为“断定,推断出”,其后可接由that引导的宾语从句。

【拓展】

conclude from意为“从……推断,从……中得出”。

StepⅣ.Listen and sing along

1.Show Let’s Do It!No. 4 on PPT.

2.Read and discuss the lyrics of the song as a class.

3.Play the audiotape for the song.Play it once and ask the students just to listen.

4.Play the song a second time and ask the students to sing along.

StepⅤ.Task

1.Show Let’s Do It!No. 3 on PPT.

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?

2.Instruct the students to work in groups of three to try the experiment and record the process using the scientific method.

3.Have the students try the experiment with some variations and record their results.

4.Ask each group to present their findings to the class. StepⅥ.Practice 1.让我们做个实验吧! Let’s

! 2.将玻璃罐子迅速地翻过来。

the

jar

quickly. 3.我相信她能通过考试。

I

she could

the exam. 、

4.硬纸板能承受住水。

The

will

the water. 5.那叫作科学方法。

That’s

the

. StepⅥI.Ssummary and homework