新课标人教版必修四unit 2 Working the land Chemical or Organic Farming课件 （共24张PPT）

课件24张PPT。Have you ever been to the farm?
Do you still remember the experience of working the land?Students are ____________（犁地）. ploughingThe farmer is sowing ________ in the soil.seedsStudents are carrying the _______ _____.
（天然粪便） natural waste They are removing the _______.weedsTo protect the crop, farmers have to kill off the hamful _______.pestsfertilizer How many kinds of fertilizers do farmers use?chemical fertilizersWhich kind of fertilizer do organic farming(有机农业) prefer? What do you know about "organic farming"?animal wastenatural fertilizersReadingCHEMICAL OR ORGANIC FARMING?Task 1: Go through the passage quickly, and underline the topic sentence of each paragraph and then complete the main idea of each paragraph.
Para.1: ______ __________ used to be common, but
recently scientists have discovered its
harmful effects.
Para.2: There are some _________ of chemical
fertilizers.
Para.3: People begin to turn to _______ _________
Para.4: Farmers use different ________ in organic
farming.
Chemical fertilizersproblemsorganicfarmingmethods
Judging from the structure of the whole passage, what's the writing style of the passage?

A. argumentation
B. narration
C. exposition
Para.1becausehoweverover the past half centuryhowever recentlyLet's draw a mind-map(思维导图) of Para. 1
(first find out the linking words/phrases )Group Work Task 2:
Work out the mind-map（para.2, 3, 4）, retell the paragraph.
(Group1、2&3负责para.2; Group4、5&6负责para. 3; Group 7&8负责para.4 )
Share your mindmap and retell the paragraph;
(实物投影)
Task 3: finish the exercise after listening to other groups' retelling.para. 2What problems are caused by chemical fertilizers?
1. ________ the land
2. stay in the crop; get inside the
crops; ___ ____ in people's bodies;
lead to cancer or illnesses
3. grow too fast to be full of ________
damage build upnutritionPara. 3 Organic farming is simply farming without using ___________. They focus on keeping their soil rich and _______________.
any chemicalsfree of disease
What is organic farming?para. 4What are methods of organic farming?
1. use natural waste;
2. _____ _____in each field every few
years;
3. use different _____ of soil;
4. plant _____ between cropschange croplevelsgrass Two students from SS environmental association is having an interview with two agricultural experts about organic farming
Group 1to4: based on passage, design questions for the students from SS environmental association (write down at least three questions) (5W questions; be curious; willing to learn; good manners)
Group 5 to 8: agricultural experts (be ready for any question); review the mind maps, get familiar with the information (knowledgeable and professional; be patient with the questions)
Sser: Good morning, Professor...We are students from...Would you mind ...
Experts:...
Sser: We, students in Ss are curious about what organic farming is? Can you explain a little bit?
Organic food is considered natural and healthier, but some people don't think so, why?)
......
(make sure every student have
equal chance to conduct the
conversation)HomeworkRead material 2
Is Organic farming really that good?
work out the mind-map of the whole passage;
share it with your classmates next class