Unit 13
Teaching Aims:
1.Learn and master the following words and phrases:
cube, property all the way, that is….
2.Improve the students’ reading ability
3.Enable the students to realize that it is important to protect that water on our planet.
Teaching Important Points:
1. Improve the students’ reading ability
2. Master the following phrases
All the way, that is , mix with, take advantage of , manage to do
Teaching Difficult Points:
How to make the students understand the reading passage better
Teaching Methods:
1. Discussion before reading to make the students interested in what they will learn
2. Fast reading to get a general idea of the text
3. Discussion after reading to make students understand what they’ve learned better
4. Careful reading to get the detailed information in the text
Teaching Aids:
1. the multimedia 2. the blackboard
Teaching Procedures:
Step 1 Warming up
Collect as many words as possible related to water.
(Ice ocean lake river rain sweat fish steam)
What properties or characteristics do you know about water?
(Colorless tasteless odorless three forms absorbing heat dissolving feeling wet)
Group work:
What property of water does each of the four experiments illustrate?
What causes this phenomenon?
What’s this phenomenon related to?
Experiments
Experiment 1 shows how air pressure causes a piece of thick paper to cling to an upturned glass of water.
Experiment 2 illustrates how substances with different density behave when placed in the same container.
Experiment 3 is an example of how water dissolves substances and objects.
Experiment 4 illustrates some of the differences between salt water and fresh water.
What other properties of water do you know?
What do you think causes the following phenomena?
We can get a lot of nutrients in the soup.
Wood floats on water while iron sinks.
The coastal areas are often neither too hot nor too cold.
Why can some living things live at the bottom of the ocean where there is no sunshine?
Step 2 Pre-reading
Questions related to the subjects
What is/ are _ the properties of water?
What does (one property of water) look like?
What are different parts of the oceans?
What can the oceans be compared to?
How does the oceans work?
What are some examples of life in the ocean?
Activity 1. Structure of the passage
A: 1 minute to skim the passage, focusing on the titles (title and subtitles)in the text and then fill in the chart below. You do not need to read the whole text.
THE PROPERTIES OF WATER：SALINITY OCEAN MOTION HEAT CAPACITY DENSITY CHEMICAL STRUCTURE
B: Use the topic of each paragraph and the structure above to make six questions. Work in groups and fill in the questions. Write down your answers and anything else you know about the topic.
What is / are_________? What can_________ be compared to?What does ________ look like? How does________work?What are different parts of_________? What are some examples of________?
Activity 2. Word Study
A: Look at the titles of the reading. Which of the following words do you think will be in the reading passage when we talk about this topic.
Freezing dissolve decrease sensitive stable absorb range float
range: to vary within specified limits
freezing:
dissolve: to reduce (solid matter) to liquid form; melt
float: to cause to remain suspended without sinking or falling
decrease: to grow or cause to grow gradually less or smaller, as in number, amount
absorb: to take something in
stable: resistant to change of position or condition
sensitive: responsive to external conditions stimulation
Step 3 Fast Reading
Answer the following questions:
1.What are the properties of water?
2.What does the earth look like?
3.What are different parts of the ocean?
4.What can the ocean be compared to?
5.How does the special air-conditioner-the ocean work?
6.What are some examples of species in the ocean?
Find out as many words and phrases as possible about water properties in the text.
True or false:
（T）1．Water is a liquid at room temperature, and it has a relatively high freezing point.
2．The reason why water can dissolve most substances on earth is that water has high heat capacity.
3.Like all the other substances, water gets smaller (contract 缩小) when it freezes.
(T) 4.Pure water has a higher freezing point and lighter than salt water.
(T) 5.The salinity of the earth’s oceans is about 3.5%.
6.When water freezes, its density increases.
7.Other recourses such as oil, gas, gold etc is as precious as a drop of rain.
Who can tell me the general idea of the text?
The passage mainly tells us it is water that makes the ocean so important to all the living things in the world.
Step 4 Careful Reading
Find out some basic facts about life in the oceans
Basic facts about life in the oceans from the opening paragraph :
Life on earth began in the oceans about three billion years ago;
99% of the living space on earth is in the oceans;
There are about five million (known) species in the oceans;
Life in the oceans ranges from tiny plankton to giant whales.
Step 5 Activity 3. Finding Topic Sentences
Topic Sentence of the text:
Paragraph: 7
Sentence:Learning about the properties of water helps us understand life on our planet.
Topic Sentence of CHEMICAL STRUCTURE:
Paragraph: ____2____
Sentence: The chemical structure of water makes it an excellent medium for life.
Topic Sentence of SALINITY:
Paragraph: __3____
Sentence: The salinity of the earth's oceans is about thirty-five parts per thousand, meaning that there are about thirty-five grammes of dissolved solids and gases in one kilogramme of water.
Topic Sentence of DENSITY:
Paragraph: ___4_____
Sentence:The density of pure water is 1,000 kg/m3, meaning that one cubic metre of water weighs one thousand kilogrammes.
Topic Sentence of HEAT CAPACITY:
Paragraph: __5______
Sentence:Heat capacity is the amount of energy it takes to raise the temperature of a substance by one degree centigrade.
Topic Sentence of OCEAN MOTION:
Paragraph: __6______
Sentence:Since changes in salinity and temperature affect water's density, the water in the ocean is always moving.
Step 6 Activity 4. Comprehension A
Paragraph 1.
marine life: (definition based on the text)
Ninety-nine percent of the living space on earth is in the oceans.
incredibly: unbelievably doubtfully extremely questionably
Life in the oceans ranges from the tiniest plankton all the way up to giants like sharks and whales. (paraphrase)
A diverse world Natural selection Life first appeared in the blue seas.
99% of the living space on earth is in the oceans.
What does this fact result in? Marine life is incredibly rich and varied.
Can you give some specific numbers or examples? 5 million species in the oceans
What does this fact imply? Do you agree
Paragraph 2.
H2O:2_______________ + 1____________ = 1___________
medium: average channel means condition
polar: + – ↑ ↓
positive end: + – ↑ ↓
negative end: + – ↑ ↓
Normal state of water: solid liquid gas
Why is the chemical structure of water important?
1. Because water is polar, it can break down both solids and gases.
2.The nutrients in whatever falls into the ocean quickly become available to other living creatures.
3. The chemical structure of water also makes it different from almost everything else on earth.The nutrients in whatever falls into the ocean quickly become available to other living creatures. (paraphrase)
Water is an excellent medium for life.
Why do you agree with it?
1.Water is a liquid at room temperature and has a relatively high freezing point;
2.All living creatures need food to survive, but on many occasions the nutrients become available to living things only when they are dissolved by water.
Water’s unique chemical structure
Can you give some other examples which are also resulted from water’s unique chemical structure?
1.We can get a lot of nutrients by drinking soup.
2.Plants can pull water up their roots via a capillary(毛细管) process.
Paragraph 3.
sea water (salt water) =dissolved gases+ dissolved solids +pure water
salinity of sea water affects: weight and freezing point
salinity of sea water: 35‰ 35%
The salinity of the earth’s oceans is about 3.5%.
What does this mean?
There are about thirty-five grams of dissolved solids and gases in one kilo of water.
In winter water in some containers or small rivers often freezes while that in seas not? Can you explain it?
1.The salinity of sea water can affect the freezing point of water.
2.Sea water has a lower a freezing point, so even when the temperature of sea water falls below 0℃, sea water is still liquid.
Paragraph 4.
Factors of density: mass and volume
Unit of density: kg/m3= kilogrammes per cubic metre
Density of pure water: 1,000 kg/m3=one cubic metre of water weighs one thousand kilogrammes When water freezes, its density decreases. If it did not, the oceans would be frozen solid. (paraphrase)
What is density?
Density is the relationship between mass and volume and is measured in kg/m3, reading kilos per cubic meter . The density of water is 1,000 kg/m3.
Does it also goes for the phenomenon that ice looks larger than water does?
Ordered molecular structure of frozen water (ice)
Semi-ordered molecular structure of liquid water
What do different densities in the ocean result in?
Water in the ocean is always moving.
What phenomena can this result help us explain? Please give examples.
1.Ocean motion helps move nutrients around and adds energy to the marine ecosystems.
2.Different marine creatures live in different levels of the ocean. (Because of the foods they need, sunshine etc.)
Paragraph 5.
Heat capacity: water temperature substanc energy
Opposite word/phrase of absorb: give off change create
Paragraph 6.
How does the water in the ocean move?
Dense water sinks and less dense water is pushed to the surface.
Paragraph 7.
Main idea: significance of water to nature
Water, which seems so simple and common, is what makes life possible. Of all the resources on earth -- oil, gas, gold and so on -- nothing is as precious as a drop of rain. (paraphrase)
Read following statement and think what conclusion you can draw? Or what property does it refer to? It is said that a man of 60kg loses about 1L water through breath and skin evaporation (皮肤蒸发) every day. In other words, 539kcal heat is released in these two ways. If so much heat were kept in human body, it would raise body temperature by 9℃.
Can you imagine the result? Water has a relatively high heat capacity and can accommodate the climate automatically. It can absorb and release a lot of heat without big changes in its temperature, thus creating a stable environment.
Here are some more familiar phenomena, what property of water are they related to?
1.The coastal areas are often neither too hot nor too cold.
2.Ice floats on water.
3.When the sea water in a container is evaporated (蒸发), there will be some salt left.
4.Irrigate in winter can help raise the soil temperature.
5.People swimming in the Dead Sea float; they can even read a paper while lying on their back in the water.
Homework
Try to think as many examples as possible to show that water is made use of to bring benefit to human beings.
Step 7 Further Understanding and Language Study
1.come up with想出（计划、答案等）
He couldn’t come up with an answer when I asked him why he was late.
come about发生 come across偶然遇come out 出版
2.benefit….from 从……获益be of benefit to 对……有益
3. take advantage of 对……加以利用
4.make notes of=take notes of 记下
Language points in the text
1.incredibly adv. (extremely or unusually)难以置信的e.g.The water is incredibly hot.
2.range vi.range from A to B e.g.Their ages range from 25 to 50.
His interests ranged from chess to canoeing.
3.all the way 一直 ，一路上,完全
4.But the way the water molecule…e.g.I don’t like the way (in which/that) he looks at me.
They admired the way (in which/that) she dealt with the crisis.
5.that is (to say) (which means)
e.g.A week later,that is,May 1 is her birthday.也就是说
He is a local government administrator,that is,he is a Civil Servant.
6.break down v.毁掉, 压倒, 倒塌, 中止, 分解
7.available adj.(that can be used or obtained)可用的，可获得的
e.g.Tickets are available at the box office.The book is available to all the students.
8.on earth 在世界上，究竟，到底
9.even though/if 即使……尽管……Even though he is poor,she loves him.
Even though he's 24 now, he's still like a little child.
I can still remember, even though it was so long ago.
10.say 插句中“假定，比如”What would you do if you got,say,a million dollars?
11.take advantage of (make use of something well
e.g.They took full advantage of the hotel’s facilities.
12.be sensitive to something (affected easily by something)对……敏感
e.g.She is very sensitive to other’s words.
13.keep…steady使……稳定
Important sentences
1.Life in the oceans ranges from the tiniest plankton all the way up to giants like sharks and whales.海洋里有从最小的浮游植物一直到像鲨鱼和鲸鱼这样的庞然大物。(P1)
2.Water is actually quite simple,but the way the water molecule is formed gives water its unique properties.水实际上很简单，但水分子形成的方式赋予了水独特的性能。（P2)
3.The nutrients in whatever falls into the ocean will quickly become available to other living creatures.任何落入海洋里的物质中的营养物都会很快被其他生物所吸收利用的。
whatever“无论……东西”可引导名词性从句。如You can eat whatever your like.
Whatever is left over is yours.
4.Heat capacity is the amount of energy it takes to raise the temperature of a substance one degree centigrade.热容量是指将一种物质的温度升高一摄氏度所需的能量。
It 前面省略了关系代词that/which.不定式引导的是真正的主语
5.The water in the oceans also keeps the temperature of the earth steady by absorbing and giving off heat.
由于海水的吸热和释热的作用，从而使地球的温度保持稳定。
We should do all we can to protect water from being polluted!
Step 8 Activity 6. Summary
Features of Science Exposition：A. Sentence Structure:B. Vocabulary:C. Tense:
D. Text Structure:
INTEGRATING SKILLS
Teaching Aims:
1. Review modal verbs
2. Do some exercises to review
Teaching Important Points:
Review modal verbs
Teaching Difficult Points:
How to help the students correctly use the modal verbs
Teaching Methods:
1. Review method to help the students remember all the modal verbs
2. Individual work or group work to make every student work in class
Teaching Aids:
1. the multimedia 2.the blackboard
Teaching Procedures:
READING:NATURE'S NURSERY: ESTUARIES
Step 1 Lead-in
1.How much do you know about them? Is the economy there well-developed or not?
2. Which city is the most developed? Why?
3.Can you tell what map it is? Where is it?
4.Is the water here salty or fresh?
5.What’s the place where river and the ocean meet?
Step 2 Skimming:
Find the definition of an estuary
An estuary is the body of water where a river meets the ocean. Salt water from the ocean and fresh water from the river mix together in an estuary. This mixing of fresh and salt water creates a unique environment filled with life of all kinds－a zone between the land and sea.
What kinds of function of estuaries have been mentioned in the passage?
1.Great places for nature’s young animals clean our water by absorbing nutrients and pollutants from water coming from inland sources;
2.Provide both recreation and education for human beings.
Discussion:
1.What living conditions do you think are needed for nature’s young ones?
2.Do estuaries have such conditions for them?
Step 3 Scanning
Read the passage and answer the following questions.
1. Why are estuaries such good places for nature’s young ones?
In estuaries, animals can enjoy all the benefits of the oceans without having to face many of its dangers.
Tides provide energy for the ecosystems, but estuaries are protected from waves and storms by islands, mud or sand.
Nutrients from both the land and the ocean arrive in estuaries.
2. What does density mean in this passage?It means the number of species per area.
3. How do you estuaries affect the water that passes through them?
They absorb nutrients and pollutants from water coming inland sources, thus cleaning our water.
4. Why are estuaries more sensitive to pollution than other areas?
Because estuaries act as filters(过滤器), many pollutants end up in them.
5. Why are estuaries important to human beings?
① Estuaries provide both recreation and education for human beings.
People can fish, swim and have fun on the beach.
Scientists and students have endless opportunities to study a variety of life in the habitat.
② Estuaries also contribute to the economy through tourism and fishing
Finish the following passage with words from the text.
Estuaries are bodies of water along coasts that are formed (形成) when fresh water from rivers flows into and _mixes with salt water from the ocean. In estuaries, the fresh river water is blocked from streaming into the open ocean by either surrounding mainland, or islands. This mixing of fresh and salt water creates a unique environment filled with life of all kinds - a zone between the land and sea known as an estuary.
The estuary gathers and holds a variety of life－giving nutrients from the land and from the ocean, forming an ecosystem that contains more creatures than any other habitat
on the earth. Estuaries are also important for human beings. They protect water quality by absorbing pollutants from water coming from inland sources. They are centers for entertainment (娱乐) and education. Estuaries, in short, are treasures.
Step 4 Activity 1. Finding Topic Sentences
Topic Sentence of Paragraph: _1____
Sentence:As the oceans are the source of life on earth, the estuaries are our planet's nurseries.
Topic Sentence of Paragraph: _2____
Sentence: Estuaries are great places for nature's young ones
Topic Sentence of Paragraph: __3___
Sentence:Estuaries are also important because they absorb nutrients and pollutants from water coming from inland sources, thus cleaning our water.
Topic Sentence of Paragraph: ___4__
Sentence: Estuaries provide both recreation and education for human beings.
Provent…against/from Stop…from Keep..from
Step 5 Activity 2. Structure of the passage
Step 6 Activity 3. Answering the questions
1Why are estuaries such good places for nature's young ones?
2 What does density mean in this passage?
3 How do estuaries affect the water that passes through them?
4 Why are estuaries more sensitive to pollution than other areas?
5 Why are estuaries important to human beings?
Step 7 Activity 4. Word Study
Pollutant ：something that pollutes, especially a waste material
estuary：the body of water where a river meets the ocean
recreation：refreshment of one's mind or body after work through activity that amuses or stimulates
mammal：warm-blooded vertebrate animals
reproduce：to generate (offspring) by sexual or asexual means.
erosion腐蚀, 侵蚀：the process of eroding or the condition of being eroded
Step 8 Writing
Tip 1 If you are describing a process,
1.You should explain each step in the order it happens.
2.Tell the readers about the causes and effects and use words like first, second, then, etc to show the order of the steps.
First…Second…Third/ Then…Last…
Tip2
If you are writing about something that has several parts, describe each part and explain its function and structure. The following questions may help:
1.What is it ? How many parts is it made up of?
2.What‘s the structure of each part? How does it work?
3.What’s the function of the thing?
Imagine that your science teacher ask you to explain one of the following questions:
1.Why does an ice cube float?
2.What will happen to a piece of metal if you put it in water?
3.Why do so many species live in estuaries?
4.Why have so many cities been built by estuaries?
Choose one of the questions and write a passage, using what you know about nature and science and what you have learned from this unit.
Step 9 Homework
Choose one of the questions and write a passage, using what you have learned about water from this unit and new words and sentence structures of this unit as well.