人教版必修4Unit 2 Working the land Reading课件(共27张PPT)

(共27张PPT)
Unit 2 Working the land
READING
Why should we recall our respect for food
A PIONEER FOR ALL PEOPLE
READING
father of hybrid rice
＊He is one of China's most famous scientists.
＊His sunburnt face makes him look like a farmer.
＊He helps to increase the output of rice and rid the world of hunger.
Read the text and find out what aspects are covered in each paragraph
Para.1
Para.2
Para.3
Para.4
introduction
biography
personalities
dreams
occupation
appearance
major achievements
education backgound
reason for doing research
contributions and meanings
hobbies & values
1.Why is Dr. Yuan called “a pioneer”
2. What are Dr. Yuan 's contributions to China and to the world (1/5, 60%, 22%, 7%, twice)
3. What are Dr. Yuan's dreams？
1.Why is Dr. Yuan called “a pioneer”
In 1973, he became the first agricultural pioneer in the world to grow rice that has a high output.
2. What are Dr. Yuan 's contributions to China and to the world (1/5, 60%, 22%, 7%, twice)
This special strain of rice makes it possible to produce 20% more of the crop in the same fields.
Now more than 60% of the rice produced in China each year is from this hybrid strain.
These increased harvests mean that 22% of the world's people are fed from just 7% of the farmland in the world.
Using his hybrid rice, farmers are producing harvests twice as large as before.
export
n. [U/ C]
＊export earnings/ markets
＊Wool is one of the chief exports of Australia.
＊Australia actually exports the most diamonds and coal in the world
v.
What kind of person is Yuan Longping
Describe his personal qualities and personalities.
Find clues from the text.
eg. I think he is hardworking, because he has
sunburnt face and a slim, strong body.
Work in groups, select a speaker to take notes. All
members take turns to contribute your idea.
It's nice to be important, but it's more important to be nice!
--What do famers need to grow food
--They need ...
Lead-in
fertilizer
How many kinds of fertilizers do you know
chemical fertilizer
natural fertilizer
chemical farming
organic farming
Lead-in
Using Language
CHEMICAL
OR ORGANIC FARMING

Read for Structure
Underline the topic sentence of each paragraph.
What are some of the problems caused by chemical fertilizers First, they damage the land by killing the helpful bacteria and pests as well as the harmful ones. Chemicals also stay in the ground and underground water for a long time. This affects crops and, therefore, animals and humans, since chemicals get inside the crops and cannot just be washed off. These chemicals in the food supply build up in people's bodies over time. Many of these chemicals can lead to cancer or other illnesses.In addition, fruit, vegetables and other food grown with chemical fertilizers usually grow too fast to be full of much nutrition. They may look beautiful, but inside there is usually more water than vitamins and minerals.
A
B
With these discoveries, some farmers and many customers are beginning to turn to organic farming. Organic farming is simply farming without using any chemicals. They focus on keeping their soil rich and free of disease. A healthy soil reduces disease and helps crops grow strong and healthy. Organic farmers, therefore, often prefer using natural waste from animals as fertilizer. They feel that this makes the soil in their fields richer in minerals and so more fertile. This also keeps the air, soil, water and crops free from chemicals
Read for Structure
Underline the topic sentence of each paragraph.
Organic farmers also use many other methods to keep the soil fertile. They often change the kind of crop in each field every few years, for example, growing corn or wheat and then the next year peas or soybeans. Crops such as peas or soybeans put important minerals back into the soil, making it ready for crops such as wheat or corn that need rich and fertile soil. Organic farmers also plant crops to use different levels of soil, for example, planting peanuts that use the ground's surface followed by vegetables that put down deep roots. Some organic farmers prefer planting grass between crops to prevent wind or water from carrying away the soil, and then leaving it in the ground to become a natural fertilizer for the next year's crop. These many different organic farming methods have the same goal: to grow good food and avoid damaging the environment or people's health.
Read for Structure
Underline the topic sentence of each paragraph.
C
D
Over the past half century, using chemical fertilizers has become very common in farming. Many farmers welcomed them as a great way to stop crop disease and increase production. Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land and, even more dangerous, to people's health.
Read for Structure
Underline the topic sentence of each paragraph.
Read for Structure
the topic sentences of each paragraph.
A. What are some of the problems caused by chemical fertilizers
B. With these discoveries, some farmers and many customers are beginning to turn to organic farming.
C. Organic farmers also use many other methods to keep the soil fertile.
D. Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land and, even more dangerous, to people's health.
D A B C
Read for Structure
1. What's the function of the first paragraph
to __________ the topic
2. Which two paragraphs can be grouped together
Para.2 problems
Para. 3 organic farming
Para. 4 organic farming methods
3. What's the relationship between para.2 and para. 3&4
para.2 ----Chemical farming causes the problems.
para. 3&4 ---Organic farming _______ the problems.
introduce
solves
exposition
a systematic interpretation or explanation (usually written) of a specific topic
1. Why have chemical fertilizers been so popular in farming over the past half century
2. What have scientists discovered recently
stop... and increase
long-term use of chemical fertilizers can cause damage to...
Read for Details
How many problems can be caused by using chemical fertilizers
Read Para.2 and answer
There are three problems.
First, they can damage... as well as... Chemicals also stay in the ... and ... In addition, ... grow too fast to...
Organic Farming
Read Para.3&4 and fill in the blanks
Methods Advantages
Use _______ waste from animals. Change ____________ in each field every few years. Plant crops with different depths of _____. Plant _______ between crops. make the soil _____ in minerals and more ______.
Put __________________ back into the soil, making it rich and fertile.
Use ______________ of soil.
Prevent wind or water from ___________ soil and act as _________________.
natural
richer
fertile
the kind of crop
important minerals
roots
different levels
grass
carrying away
The same goal: to grow... and avoid...
natural fertilizer