高中英语必修4unit2：Using language(共20张PPT)

Read again and choose the best answer.
1. Which statement is WRONG according
to the text?
D
A. All crops are organic.
B. Recently, the term “organic farming”
the soil from being blown away
The main idea of each paragraph
pay attention to the first and the last sentence of each paragraph
The main idea of each paragraph P1. Long-term use of chemical fertilizers can
cause damage to the land and people’s health.
P2. Problems caused by chemical fertilizers.
P3. Farmers and customers turn to organic farming.
P4. Other methods to keep the soil fertile.
Two kinds.
Better
chemical fertilizer chemical farming
natural fertilizer organic farming
Discussion: Which kind of farming is better?
用化学肥料和有机肥料的区别:
cow dung
affect crops--animals by staying in the ground
and humans
and underground water for a long time
increase production
lead to cancer /illnesses
have less nutrition
by building up in people’s bodies over time
by growing too fast
Paragraph 3 advantages of organic farming:
• No use of chemical fertilizers • Keep soil rich in mineralsand free of disease • helps crops grow strong and healthy • Keep the air, soil, water and crops free from chemicals
3. What is the advantage of using chemical fertilizers? D A. Leaving chemicals in the ground for a long time is good for water supply. B. They can get the soil exhausted. C. They can kill helpful bacteria. D. They can kill harmful pest.
Paragraph I
1.Why are chemical fertilizers so popular in farming today?
A.Because they are cheap. B.They are a good way to stop crop
disease and increase production. C.They can cause damage to the land. D.They do good to people’s health.
has gained another meaning.
C. All farmers use fertilizers.
D. Scientists believe some chemical
fertilizers are better for people.
2. Which is not the reason why organic farmers prefer natural waste from animals? C A. It can keep the food free from chemicals. B. It can keep the air, soil and water free from chemicals. C. It can kill harmful pests. D. It can make the soil richer in mineral.
use different levels of land prevent…from…, a natural fertilizer
What is the main goal for using organic farming methods?
To grow good food and to avoid damaging The environment or people’s health.
Unit 2 Working the land
Using lang OR ORGANIC FARMING?
How can farmers make the plants grow well? Add fertilizer into the soil
How many kinds of fertilizers do farmers use?
4. The organic farmers do the followings
except __A____.
A. adding chemicals fertilizers which is rich in mineral
B. changing crops every two or three years C. planting seeds in different layers of the soil D. planting grass between crops to prevent
Paragraph 2
Chemical farming
advantages problems
cause
stop crop disease
damage the land
by killing the helpful bacteria and pests as well as the harmful ones.
use as fertilizer?
Natural waste from animals.
Paragraph 4 Find and write down the
methods and advantages in the passage.
Organic farming
methods
use natural waste
change the kind of crop plant crops with different levels of soils plant grass between crops
advantages
make the soil rich in minerals
put minerals back into soil, making…
Answer the questions. 1. What is “organic farming”? It refers to crops growing with natural rather than chemical fertilizers. 2. What do organic farmers prefer to
chemical fertilizer
ORGANIC FARMING
Organic farming is simply farming without using any chemicals.
Let’s learn more about chemical and organic farming!