Unit 13

The Water planetThe Water planet

The earth is a water planet.

_________ makes the ocean such

a great place to live in.

Step 1. Preview Task( 预习任务 )be sensitive to mass and volumebe measured in dissolved take advantage of become available to be frozen solid room temperaturea freezing point keep …steady

对…敏感质量与体积以……测量

溶解的 对……加以利用 对…成为可能

被结成固体 室温

冰点 保持稳定

Structure of the Structure of the passagepassage 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. CHEMICAL

STRUCTURE

SALINITY

THE PROPERTIES OF WATER

DENSITYHEAT CAPACITY

OCEAN MOTION

Chemical structure A metal spoon sinks into a glass （化学结构） of water

Salinity We put a bottle of hot water under the（盐度） quilt in winter and it will keeps us warm

Density If some oil goes into the sea by mistake ,（密度） it will soon spread to quite an area Heat Capacity We put a block of sugar into a glass of water and stir, and the whole glass of （热容量） water will become sweet

Ocean Motion Salt water won’t freeze at zero（海洋运动）

Step three: Match the facts with proper topics

Fast Fast ReadingReading

Finding Topic Sentences

Topic Sentence of the text :Paragraph: ________Sentence:

Topic Sentence of SALINITY :Paragraph: ______Sentence:

Topic Sentence of CHEMICAL STRUCTURE :Paragraph: ________Sentence:

step one:step one: Finding Topic Sentences

7

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2

Learning about the properties of water Learning about the properties of water helps helps us understand life on our planet.us understand life on our planet.

The chemical structure of water makes it an The chemical structure of water makes it an excellent medium for life.excellent medium for life.

The salinity of the earth's oceans is about The salinity of the earth's oceans is about thirty-five parts per thousand, meaning that thirty-five parts per thousand, meaning that there are about thirty-five grammes of dissolved there are about thirty-five grammes of dissolved solids and gases in one kilogramme of water.solids and gases in one kilogramme of water.

Topic Sentence of HEAT CAPACITY :Paragraph: ________Sentence:

Topic Sentence of DENSITY :Paragraph: ________Sentence:

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The density of pure water is 1,000 kg/m3, meaning The density of pure water is 1,000 kg/m3, meaning that one cubic metre of water weighs one thousand that one cubic metre of water weighs one thousand kilogrammes.kilogrammes.

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Heat capacity is the mount of energy it takes to raise Heat capacity is the mount of energy it takes to raise the temperature of a substance by one degree the temperature of a substance by one degree centigrade.centigrade.

Topic Sentence of OCEAN MOTION :Paragraph: ________Sentence:

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Since changes in salinity and temperature affect Since changes in salinity and temperature affect water's density, the water in the ocean is always water's density, the water in the ocean is always moving. moving.

Step two:True or false1. There are about five billion species in the oceans ranging from the tiniest plankton to giants like sharks and whales. ( )2. The water molecule is made of two hydrogen atoms and one oxygen atom. ( )

F

F

billion --- million

made of --- made up of

3. Pure water has a higher freezing point and is lighter than salt water. ( )

4. If a substance has a density 888kg/ m3, it will float on Water. ( )

5. The heat capacity of water is relatively high, so most animals and plants don’t like living in the ocean. ( )

6. The most important thing we can learn about water is that we must protect it and use it wisely. ( )

T

T

F

T

Step three: Careful reading

Some basic facts of each paragraph!

About 75 %

____ of the living space on earth is

in the oceans.

Marine life is incredibly_________________.

99%

rich & varied

1.What percentage of the earth is covered by water?

There are about _____________species, _______________ the tiniest plankton

_____giants like sharks and whales.

2. How many species are there in the oceans?

five millionranging from

to

*sea water (salt water) = ________________+ ________________+_________________ *The salinity of sea water affects: ___________ and_______________

dissolved gasesdissolved gases

dissolved solidsdissolved solids pure waterpure water

weightweightfreezing pointfreezing point

salinity of sea water: 35‰ 35% √√

*It is made up of_______________&__________*The water molecule is ______*It has a slightly _______and a slightly_________end. *The normal state of water is__________

2 hydrogen Atoms2 hydrogen Atoms 1 oxygen atom1 oxygen atom

polarpositive negative

liquid

Factors of density: ___________and ___________

Unit of density: _____________ =

___________________________.

Density of pure water: _____________=

________________________________________________

massmass volumevolume

kg/m3kg/m3

kilogrammes per cubic metre kilogrammes per cubic metre

1,000 kg/m31,000 kg/m3

1 cubic metre of water 1 cubic metre of water weighsweighs 1,000 kilogrammes 1,000 kilogrammes

*The heat capacity of water is ___________________. *Water can______ and _________heat without_________ the _____________of the oceans.

How does the water move in the ocean?

relatively highrelatively highabsorbabsorb

Water is _____makes life possible.whatwhat

Dense water sinks and less dense water is Dense water sinks and less dense water is pushed to the surface.pushed to the surface.

give offgive off changingtemperature

1. Based on Para. 1, the author tells us that there are various species in the oceans, indicating that ____ .

A. Water plays a great role for marine life.

B. Ocean is a good place for life.

C. There are many reasons for tiniest plankton and giants like sharks and whales

D. Ocean is part of the earth

Step four: Reading Comprehension

A

2. The water in the ocean is always moving since _____ .

A.The temperature of sea water is relatively high.B. Water’s density affect changes in salinity and

temperature.C. Changes in salinity and temperature have effect

on water’s density.D. Waters in rivers always flow into the ocean.3.Generally speaking , most animals & plants are

______ to large or suddenly changes in temperature.

A.generous B. objective C. subjective D. sensitive

C

D

Seen from the space, the earth is an ______ planet. Water is very important to life. It is said that life on the planet began in the ______. Marine life is _________ rich. Life in the oceans _________ from the tiniest___ ____ ___up to giants like _____and ____ . The water molecule ___ _____ ____ ___ 2 hydrogen atoms and 1 oxygen atom. Water exists in three states. It has a relatively high __________ point.

ocean

oceans incrediblyranges

all the way sharkswhalesis made up of

freezing

Step five: summary

Fill in the blanks

Salt water has a ________ freezing point and is ________ than fresh water. There are many _____ of marine life. There is life even on the ________ of the deepest oceans. The creatures on the ocean floor manage to survive without ________ and get

_________ from other sources

lowerheavier species

bottom

sunlightenergy

Post—reading

Step one: RetellingRetelling

property

What is it?

What is it good for?

chemical

structure

density

2 hydrogen atoms and 1 oxygen atom

It can break down both solids & gases and good for living things to live in the ocean ,especially...

It helps small creatures to float.

Density is the relationship between mass and volume.

Property What is it? What is it good for?

heat capacity

ocean motion

It is the amount of energy it takes to raise the temperature of a substance one degree centigrade.

It keeps the oceans and the earth at a steady temperature

The circulation adds energy to marine ecosystem and moves nutrients around.

It’s the movement of water caused by changes in salinity & temperature.

Para.1Marine life

chemical structure

Para.2

salinityPara.3

DensityPara.4

Heat CapacityPara.5

Ocean motionPara.6

1. How is the text organized?

Para.7 The importance of protecting water

Step two: Discussion

2. Why is water important?

water

1. Review the properties 1. Review the properties of water .of water .

2. Finish some work on 2. Finish some work on your workbookyour workbook