懂你英语Level-3-unit-3.docx

1、Level 3 unit 3 part1ListeningThere are many forms of life on Earth, including human beings.Life exists in a variety of conditions.Some forms of life live in a watery environment, like the oceans.Other forms of life can be found in very dry areas, like deserts.However, for any form of life to exist,

2、conditions must be right.When conditions are not right, that form of life will become extinct. Tobecome extinct means to die out completely.-What must be right for life to exist? -Conditions.-What happens if conditions are not right? Life cannot exist.Conditions must be right for life to exist.Milli

3、ons of years ago, there were forms of life that no longer exist.When conditions changed, these forms of life died out.One extinction event happened about 250 million years ago.This was the largest extinction event of all time.Many forms of life became extinct.96% of all life in the oceans died out.M

4、ost insects also became extinct.This event happened over a period of several million years.-What happened about 250 million years ago? Many forms of life became extinct.-What happens in an extinction event? Many forms of life became extinct.The causes of this extinction event are still unknown.Possi

5、ble causes include large volcanic eruptions and global warming.Some scientists believe that there were several causes.They believe that a series of events caused the extinctions.Scientists are working to better understand what really happened.-What is the one possible cause of this event? Volcanic e

6、ruptions.In modern times, we humans face changing conditions.For humans to live, we need clean air and clean water.Pollution is now a growing problem around the world.Pollution poisons the air and water that we depend on.Polluted air makes people sick and afraid to go outside. Pollutedwater poisons

7、our food supply.As a result, we never know which foods are safe to eat.Human beings cannot live in a poisoned environment.Therefore, pollution is a major threat to our existence.-What do humans need to live? Clean air and clean water.-What poisons the air and water? Pollution.Humans need temperature

8、s to be in a comfortable range.To be in a comfortable range means to be neither too hot nor too cold.With global warming, global temperatures are rising.As temperatures rise, the polar icecaps will melt.As the polar ice caps melt, ocean levels will rise.Areas of some countries will soon be under wat

9、er.People will be forced to relocate from flooded areas.-As temperatures rise, what will happen to the polar icecaps? The polar icecaps will melt.-As the polar icecaps melt, what will happen? Ocean levels will rise.In nature, even small changes can sometimes have large effects.Its difficult to predi

10、ct whats going to happen.The entire ecosystem that we depend on is changing.Some of these changes are irreversible.Irreversible changes cannot be undone.-What can small changes sometimes cause? Large effects.-What is happening to the worlds ecosystem?Ecosystem is changing.Lets hope that humans are s

11、mart enough to understand how the world is changing.With more understanding, we can make better choices about what to do.We can face the challenges of pollution and global warming.We need to do this before its too late.This planet Earth is our only home and we need to protect it.-What challenges do

12、we need to face? Pollution and global warming.We need to protect the environment that supports us.VocabularyMammals are covered by hair or fur, have a backbone, and are warm blooded.All female mammals produce milk for their young.Reptiles are covered by scales, and includes snakes, lizards and turtl

13、es.Reptiles have a backbone and are cold blooded, which means they often relied on the external source of heat.Birds are covered by feathers and are warm blooded.Most birds can fly and many types of birds migrate great distances.Most insects such as ants and bees have a small three part of body with

14、 three pairs of legs.Some insects, like mosquitoes, spread diseases that cause the deaths of many humans.Unlike animals, plants get the energy that they need from the sun.Plants convert light energy, along with carbon dioxide and water, into chemical energy.Insects dont have a backbone and most are

15、cooled-blooded.Insects such as ants and bees live in well-organized colonies.Mosquitoes cause the deaths of more humans than any other animal.Mammals include some of the most intelligent animals on earth, such as elephants and human beings.Scales and rulers are used to measure weight and length.Unit

16、s of weight include kilograms and pounds, and units of length include centimeters and inches.These instruments are used to observe very large and very small objects.Telescopes are used to by astronomers and microscopes are used by biologists and doctors.These appliances are used in the kitchens of a

17、lmost every home.Stoves are used to heat food and refrigerators are used to keep foods cool or cold.Household tools like these are used to build and repair things.Hammers are used to pound in nails and screwdrivers are used to turn a scow.If you need to pound in a nail, use a hammer.DialogueW: do yo

18、u know what day it is today?M: what do you mean? Is it a special day?W: oh, so you dont remember.M: remember what? Whats so special?W: its our anniversary. We started dating a year ago today. M:oh, really, Im sorry.-When did they first start dating? A year ago.M: just a minute. What do you think thi

19、s is?W: oh, its a necklace.M: do you like it?W: yes, I do. Its lovely, especially the red heart. May I put it on?M: no, let me do it.-What did he give her? A necklace.W: so you did remember.M: of course I remembered. Its a very special day for both of us.W: I have something for you too.M: you do?W:

20、yes, but it will have to wait until later.M: oh, I cant wait. Tell me what it is.-What would have to wait until later? Shes going to give him a gift.Do you know what today is?W: can you guess what it is?M: could you give me a hint?W: we went there six month ago.M: oh, you mean Alfredos.W: yes, are y

21、ou excited? You said you really like the food there.M: yes, thats true. I also remember the dessert. Do you?W: yes, but lets not talk about that now. Lets now ruin the surprise.-What is Alfredos? A restaurant.-What arent they going to talk about? They arent going to talk about the desert.He remember

22、ed that today is their anniversaryW: That restaurant looks nice.M: Yes, but it looks expensive.W: Lets go in and look the menu. Wow the menu looks great, especially the fish. M:Yes, it looks good, but look at those prices.-What doesnt she like about the menu? She likes the food choices.M: Lets try s

23、omewhere else.W: Sometimes its ok to spend a little money.M: Yes, but these prices are a bit too high, dont you think?W: Yes, there are a bit high. But dont you think Im worth it? Lets enjoy ourselves.M: Ah, ok, if you put it that way. Lets see if we can get a table. W:Im glad you have your credit c

24、ard.M: I sure hope the food is good.W: Stop worrying. Lets just enjoy.-Who is going to pay the bill? He will pay the bill.-How is he going to pay? He is going to use his credit card. Heis worried about spending so much moneyLevel 3 unit 3 part2ListeningQuickServe is a home repair company.It provides

25、 quick, reliable repair services to homes.QuickServe handles plumbing and electrical issues, 24 hours a day.It also cleans roofs, fixes internet connections and replaces broken windows.For a small fee, customers subscribe to the service.Its main customers are the elderly, which means older people.Wh

26、enever customers have a problem, they can call for help.There is also a small service charge for each service call.-What kind of services does QuickServe provide? Home repair servicesThe company was established 5 years ago and is growing rapidly.It started in one city but is now in 5 cities.The comp

27、any plans to expand to 10 cities within the next 24 months.In each city there is a small central office in the low-rent area of the city.The central office handles the business, advertising, payroll and billing.It also takes calls from customers, either on line or by telephone. Ittakes calls 24 hour

28、s a day, 7 days a week.-When was the company established? It started five years ago.-Where does the company locate its central offices? They locate in low-rent areas.60% of the companys employees work from their homes.When a customer calls into central office, a service employee is contracted.The se

29、rvice employee then contracts the customer and signs up an appointment.These service employees are highly trained and provide excellent service.In emergencies, such as a serious plumbing problem, service can be provided within an hour.One reason for this is that the service employees live in differe

30、nt parts of the city.They are not centrally located so its quicker and easier for them to travel to a customers home.-Where do 60% of the companys employees work? From their own homes.QuickServe has an excellent reputation.Its prices are reasonable and its services are quick and efficient.The compan

31、ys service employees are clean, polite and efficient.In this type of business, person to person contact is the key to success.With each satisfied customer, more customers subscribe.Satisfied customers recommend QuickServe to their friends.This kind of word of mouth advertising is very cost effective

32、.Cost effective means that the results are good without paying a high price. Inother words, quality service provides its own reward to the company.-What kind of customers recommend QuickServe to their friends? Satisfied customers.-What kind of reputation does the company have? It has an excellent re

33、putation.The company takes great pride in being honest with its customers.There are no hidden charges for their services.As a result, the number of customers in each city is growing rapidly.With the aging population there are more elderly people who need home repair services.These people need to hav

34、e confidence in the service provider.They dont want to be cheated.These people dont mind to pay a reasonable fee for high quality service. High quality service should be rewarded.-What should be rewarded?High quality service.-What is the company pride of? Its honest with its customers.The company pr

35、ovides a range of service plans, each with the different subscription plans.The least expensive service plan is called the basic plan.This plan provides non-emergency services with a very low service charge.The most expensive service plan is their VIP plan.The VIP plan provides emergency services 24

36、 hours a day with no additional service charge.It also provides rebates to customers who dont call for any services during the year.In addition, QuickServe gives bonus points to customers for each year they subscribe.These bonus points can be used to buy new appliances such as stoves and refrigerato

37、rs.-What kind of service plans does the company provide? It has a range of plans.-What can bonus points be used for? Buying new appliances.If the business continues to grow, the owners may decide to take the company public.This means that the public can buy shares of the company.It will then change

38、from a privately-owned company to a public company.The owners believe that their business is successful and can expand around the world. Theyalso believe that taking their company public can make them rich.-Why do the owners want to take their company public? They can become rich.VocabularyBiology i

39、s the study of life, including its structure and evolution.Biologists study how life survives and reproduces.Chemistry is the study of matter, including the structure of atoms and molecule.Chemists study how various substances interact with each other.Astronomy is one of the oldest sciences.Astronom

40、ers study the structure and evolution of the universe, including the study of stars, planets, and galaxies.Geology is the study of the structure and history of the Earth and the other planets.Geologists study different types of rocks, earthquakes, and different layers of the Earth.Mathematic is the

41、study of numbers, shapes, patterns and change. Mathematicis used by all other branches of science.Here are some types of terrible events that hurt or kill people.Earthquakes are caused by forces deep within the Earth.During earthquakes, many people are often killed by collapsing buildings and bridges.Floods happen when rivers rise and overflow their banks.Flood waters damage or destroy many houses and businesses.Fires destroy buildings, land and forests.There are many causes for fire, including lightning.In a hurricane, high winds destroy buildings, and sometime cause flooding.