高三 Unit 4 Lesson 14

发布时间:2016-2-1 编辑:互联网 手机版

Step 1 Revision

1 Revise the dialogue in Lesson 13, paying special attention to intonation.

2 Check the Ss?dialogues.

Step 2 Discussion and presentation

SB Page 20, Part 1. Get Ss to talk about the picture and describe what they can see; Read aloud the questions, then put Ss into groups of four and get them to discuss these questions briefly. Ask different groups for their answers and write these on the Bb. Then say Now read the passage and find out. Allow the Ss enough time to read the text, then put them in pairs and get them to compare their answers. Collect the answers from the class. Answers:

1 It is being built on; it is being lost by the actions of the wind and the rain; land is becoming too salty.

2 You can increase the area of farmland by irrigation; you can build dams and water your fields; you can pump water from low-lying areas; you can develop new plants which produce heavier crops; you can develop new plants which grow in poor soil; you can develop new plants that are less likely to be attacked by pests and diseases.

Step 3 Reading

Ask the Ss more questions about the passage. Let them read the whole passage carefully and answer the questions, working in pairs or small groups. Check the answers with the whole class. This is a good time to deal with any language problems. See if the Ss can guess the meaning of salty, ruin, storage, day by day, etc.

Notes:

a Feed the world: In 1994, Professor Pimentel of Comell University warned of the following problems in providing enough food for the world抯 growing population:

* By 2100 the population will be 12-15 billion, or seven times its sustainable level.

* Farmers are abandoning 25 million acres each year because of soil loss or waterlogging.

* The declining fertility of the soil will lower food production by 20% in the next 25 years.

* Topsoil is being lost 40 times faster than it can be replaced.

* Crop losses destroyed by pests have increased four times in the last 50 years.

b It is thought that: Note the use of the passive for introducing an idea.

c For one thing: This phrase is linked to The problem is... in the previous sentence. = One reason why it is difficult to feed the world憇 population is that...

d suitable for growing crops: Point out the structure: suitable +for + -ing

e And this area is becoming smaller day by day.

= And this area is becoming smaller every day. f it is being built on = buildings are being built on the land

g pests: insects or animals that destroy plants, food, etc.

h FAO: The Food and Agricultural Organization of the United Nations was founded in 1945 and has its headquarters in Rome. It has about 160 members. The purpose of the organization is to improve rural conditions, agricultural production and distribution, and to raise nutritional levels.

i in storage = while it is being stored

j damp = fairly wet. The atmosphere can be very damp during the rainy season and grain can start to go bad.

k one in ten = one person out of ten

l starve to death: a set expression = die because they do not have enough to eat

m Take the Aswan Dam for example = consider the example of the Aswan Dam

n west of the USA: particularly the desert land to the east of the high mountains

o corn crops: here, corn means maize. p low-lying areas: Many of these areas are below sea-level.

Step 4 Reading aloud

Speech Cassette Lesson 14. Play the tape of the passage for the Ss to listen and follow. Play the tape of part of the passage once more; this time the Ss listen and repeat. Pay attention to stress and intona瑃ion, also the sentence stress of the longer sentences.

Step 5 Note making

SB Page 21, Part 3. Get Ss to do this exercise individually, so that every S has to make an effort to re-read the text and extract the relevant information. If it is done in class, get Ss to check their notes afterwards in pairs. Alternatively, if you wish, you can set this exercise for homework. In that case, get Ss to check their notes in pairs at the beginning of the next lesson.

Notes:

FACTS

1 First record of agriculture (date/place): 10,000 years ago, in Egypt, the Middle East and India.

2 Present world population: almost 6 billion

3 Farming population: 1 billion

4 66% of the world抯 surface is sea.

5 11 % of the land surface can be used for

growing crops. REASONS FOR LOSS OF FARMLAND

1 It is being built on;

2 It is being lost by the actions of the wind and the rain;

3 Land is becoming too salty.

WAYS OF INCREASING FOOD PRODUCTION

1 You can increase the area by irrigation; you can build dams and water your fields; you can pump water from low-lying areas;

2 You can develop new plants which produce heavier crops;

3 You can develop new plants which grow in poor soil;

4 You can develop new plants that are less likely to be attacked by pests and diseases.

Step 6 Reference

SB Page 21, Part 4. Read the instruction and check that the Ss know what to do. Do the first two items orally with the whole class. Then let the Ss work through this exercise in pairs. Check the answers at the end. Answers:

1 about 10,000 years ago

2 1 billion people

3 how to feed a growing world population

4 the sea

5 11 % of the earth憇 land surface

6 farmland

7 desert land can now be used for growing crops

8 new types of plants

Step 7 Workbook

Wb Lesson 14, Exx. 1 and 2.

Ex. 1 should be done in class. The Ss have to make an effort to revise the text and complete the passage individually or in groups. Then check the answers with the whole class.

Ex. 2 can be done orally in class. You may change it to a Chinese-English translation exercise and get the Ss to give you the English without looking at the book.

Step 8 Consolidation

Ask Ss to say what is happening about farmland and food production in China. Get them to give specific examples, for example the Three Gorges project and other changes in their area. Are there other reasons why food production is increasing or decreasing? Get them to tell each other in pairs first, and then get pairs to tell the rest of the class.

Homework

Read the passage again and complete the notes in Part 3.

Finish off the Workbook exercises.