人教版高中英语必修四unit2_Using_language_优质课课件

C. planting crops to use the same level of soil.
D. planting grass between crops to prevent wind or water from carrying away the soil.
Consolidatioassage
Advantages of using cloth bags
1. can be recycled and reused
2. save resources 3.cheap
4. protect the environment
The following words may help you. Over the past half century, …have become very common …. Recently, however, we have been finding that they can cause damage to …. What are some of the problems caused by …? First,… With these discoveries, …are beginning to turn to …. ….
Scanning
Read the passage,and answer the questions.
1. How many problems can be caused by using chemical fertilizers?
2. What are the advantages of organic farming?
3. Which one isn't the method to keep the soil fertile? A. using natural waste from animals as fertilizer. B. changing the kind of crop in each field .
para1. A new discovery of scientists. para2. Several problems caused by using chemical fertilizers. para3. The advantages of using organic farming. Topic (present situation)
Para4. Conclusion.
Problems of using plastic bags
1. cause white pollution
2. easy to be broken
3. difficult to break down
4. do harm to the environment and people's health
Para 3. With these discoveries, some farmers
and many customers are beginning to turn to organic farming.
Para 4. Organic farmers also use many other
methods to keep the soil fertile.
2. What are the advantages of organic farming?
The farmers _______ focus on keeping their soil rich and free of disease and keeping _______ the air , soil, water and crops _________ free from chemicals.
green food
organic food
Reading
Chemical Or Organic Farming?
Skimming
Find out and underline the topic sentences of each paragraph. Para1. Recently, however, scientist have been finding that long-term use of the chemical fertilizers can cause damage to the land and, even more dangerous, to people’s health. What are some of the problems caused Para2. by chemical fertilizers?
请以“PLASTIC OR CLOTH BAGS?”为题 模仿这篇文章的篇章结构和句子结构去 写一篇说明文。
Discussion and writing
Plastic Or Cloth Bags?
Para1. Have a brief illustration of the present situation. Para2. The problems caused by using plastic bags. Para3. The advantages of using cloth bags.
Problems
Advantages
para4. Some methods to keep the soil fertile.
Methods
(conclusion)
The type of the article is_____________ exposition（说明文）
Discussion and writing
What are some of the problems caused by plastic bags? First of all, people often leave plastic bags here and there, making white pollution. What’s more, it takes a long time, more than 200 years, to break up . Last but not least, when heated, plastic bags can produce something harmful, which can build up in our body and eventually lead to cancer or other illnesses.
With these discoveries, we are beginning to turn to cloth bags. They can be used many times. People can save a lot of resources in this way. It is also a good idea to make some cloth bags by ourselves, which is interesting and cheap. Let’s use cloth bags in our daily life instead of plastic bags, not only for the environment protection, but also for the sake of our health.
Over the past half century, plastic bags have become very common in our daily life. We welcomed them as a convenient way to carry goods. Recently, however, we have been finding that they can cause damage to the environment, even worse, to people’s health.
3. Which one isn't the method to keep the soil fertile?
1. How many problems can be caused by using chemical fertilizers?
There are three problems.
First, they can damage … as well as …. Chemicals also stay in the … and …. In addition, …grow too fast to ….