懂你英语Level4 Unit 2讲课教案.docx

1、懂你英语Level4 Unit 2讲课教案懂你英语Level4 Unit 2L4 Unit 2-1Listening物种、环境The earth was born about 4.6 million years ago. The first life appeared about a billion years later. The first plant didnt appear until around 2 billion years ago. Until around 580 million years ago, life formedweresmall and microscopic

2、(微笑的 ). Since that time, lives has evolved to many different types and species. However, scientists estimate that more than 99% of them are now extinct.They have been several extinction events in the history of the earth. In the extinction event, many life forms or species of life die out. The cause

3、s of the massive extinction events are unsoughtmystery. These events are not predictable and can happen at any time. Scientists think that some of that started by asteroid pass or volcano corruption. Events like this, can change the global conditions that life depends on.One major extinction event,

4、happened about 66 million years ago. That event may have been started by a large asteroid that hit the earth. As a result, the dinosaurs and about half of the all species on the planet, died out. When the asteroid hit the earth, it started a chain of events. A chain of event is a series of events li

5、nked together, like a chain.These particular chain of events happened over a period of months and years. When the asteroid hit the earth, it caused huge cloud of dust to enter the atmosphere. This cloud of dust blocked the sun and darken the earth for a period of months. Without enoughsunlight, plan

6、ts and plant-eating animals, quickly died. With the deaths of so many plants and animals, the food chain collapsed . This led to the deaths of many more species.Mass extinction events had played important part in the evolution of life. In fact, some extinction events had helped to accelerate evoluti

7、on. For example, some mammals lived to the age of dinosaurs, but they couldnt compete. When the dinosaurs were removed, the mammals were able to compete more successfully. Once they could compete, mammal evolved to a higher state. Without the extinction event, perhaps we wouldnt be here today.Scient

8、ist estimate that there have been at least 5 massive extinctions in the pass 540 million years. They also believed that we had entered a new extinction event. Species are becoming extinct at a much faster rate than before. Instead of the asteroid and volcano corruptions, the current event is the res

9、ult of human activities. Human activities, for example, had led to global warming.Global warming is the result of an increase in carbon gases in our atmosphere. These gases trap heat from the sun, so the earth is getting warmer. As a result, sea levels are rising and weather patterns are changing. I

10、n addition, we humans are destroying habitats of many plants and animals. Cutting down forest and polluting rivers destroys the habitats of many forms of life.There is no longer any doubt that this is happening. Specials of lives are disappearing at an increasing rate. Global temperatures are rising

11、 and weather patterns are changing. Scientists are warning us that fast action is necessary to save our future. If we dont act, we may go the way of the dinosaurs.L4 Unit 2-1 vocabulary身体系统、产业、技术The body circulatory system includes the heart and blood vessels. The heart pumps the bloods to all parts

12、 of body through a network of arteries and vein.The digestive system breaks down and absorbs food into the body. It supplies the energy that the body need s for growth and repair. After digestion, excess food is turned into waste and eliminated from the body.The nervous system includes the brain, sp

13、inal cordand nerves. This is your control system. It controls your muscles and organs included your circulatory system and digestive system.The respiratory system includes your nose and lungs. It brings air and oxygen into your body and remove the carbon dioxide from the body. The lungs are where ox

14、ygen enters the bloodstream and carbon dioxide is removed.Immune system protects body against the infections and diseases. Sneezing and fever are examples of how the immune systems works. If the infection invades the body and the immune system attacks it.The control use of fire allowed people to coo

15、k food and survive in the colder climates. Fire provided the light so that people could work and socialize for longer hours.With the invention of agriculture, people can grow food and settle into communities. By growing food, people can spend less time hunting and more time on other things, such as

16、art.The domestication of animals allows people to raise and use animals for food and work. By raise herds of animals, such as sheep, people have regular supply of meat and clothing. The strength of animals such as horses and oxen was used for work and transportation.The development of tools and mach

17、ines has resulted in a more fashion manufacturing and construction. With better tools and machines, works can be done with fewer people and much lower cost.The development of science and engineering has improved many thing including communications. With understanding of electricity, telephone and ra

18、dios allow people to communicate over long distances.The use of machines has reduced the number of people needed to make things.L4 Unit 2-1 dialogue谈论手机和老板Itook a vacation last night.What are you talking about. Where did you take the vacation.I didnt go anywhere. i just left with my smartphone.How w

19、as it.It was great. I got a real magazine and read it with no interpretation . It was very peaceful. Yes, I havent done that for a long time.You know what, I begin to hate smartphone.Really, but you cant live without one, right.Yes, thats the problem.This change the way people live.Yes, I just so on

20、 documentary about that. A husband was complaining his wife that she was spending too much time on her smartphone.What happened, did they get divorced.You guess it. In the end, they got divorced.It is a bit ironic , dont you think. Smartphones were supposed to bring people together but they are pull

21、ing people apart.Yes, you are right.Hey, just a minute, Ive a message on smartphone and it cant wait.Hey, wake up and get back to work.Whats wrong with you.I m on my break sir and I had a bad headache.Well, youre not paying you to sleep.If youre going to sleep, sleep some places else.Yes, sir, it wo

22、nt happen again.You had better not.Just a minute. Dont tell me like that.What did you say.You hurt me, you dont have to treat people like that.Well, if you dont like it, I suggest you leave.Ok, I will. I pet enough of you. I will get a job somewhere else.L4 Unit 2-2 Listening概率、角度This man is holding

23、 a piece of food in this hand. The piece of food is either an orange or an apple. What cant see which its because we can see inside the box. The probability that it is an orange is equal to the probability that it is an apple. It may be an apple or it may be an orange. Its going to be one or the oth

24、er. It cant be anything else.Now lets look at it from the mans point of view. From his point of view, the probability is different. From his point of view, the possibility that he has an orange is 100% or 0%. Thats because he knows what he has. For hi m, that is not uncertainty. If he has an orange,

25、 the probability is 100%. If he doesnt have an orange, the probability is 0%. He either has it or he doesnt.From our point of view, the probability that he has an orange is 50%. From his point of view, the probability that he has an orange is 100% or 0%. So the probability depends on the point of vi

26、ew.People see things from different points of view. This often leads to arguments between the people. Here are some examples. From his mans point of view, he is relaxing. He needs to relax because he has been working too hard. He hasnt been getting sleep. His wife see things differently. She isnt aw

27、are of how hard he has been working. From her point of view, he is doing nothing. However, she knows what needs to be done around the house. It isnt fair that she has to work while he does nothing. When people see things from different points of view, they often come to different conclusion. This di

28、fferences can cause real communication problems.L4 Unit 2-2 vocabulary自然灾害、宗教Earthquakes are caused by forces deep within the earth. When the earth shakes, buildings can collapse and people can be buried inside.An explosion is a rapid, violent release of energy. Explosions can be caused by chemical

29、reaction, such as inside the engine. A spark can ignite a mixture of gases and release energy for good anddestructive purposes.Accidents are often caused by people doing foolish things or by not being careful. One major cause of accident is driving too fast. Accidentswith fire can be very serious, a

30、nd can result in very painful injuries.Epidemics are the rapid spread of a disease, such as the flu and Ebola. Throughout history, epidemics have killed millions of people. Storms are caused by changes in atmosphere, and result in high winds and heavy rains. Thunderstorms are caused by electric char

31、ges in the atmosphere, that produce lightening, which can cause forest fire. Some storms cause flooding, and major damage to homes and cities.Followers of thelslam religions are called Muslims. These Muslims are prayer inside the Moses. Muslims are called to prayer 5 times a day, beginning just befo

32、re sunrise.Christianityis based on the teaching of Jesus crisis, who lived more than 2000 years ago. Christian believe that Jesus is the son of god. Christians are often gathering in churchesor cathedralsto worship.Followers of Judaism are called Jews. These Jews are meeting inside the synagogue , which is a place of worship and study. Judaism was founded over 35 hundreds years ago, in the middle east. Judaism is based on the teaching of Moses, whom they believe its the most important prophet.Buddhism began in India a