1、This event happened over a period of several million years. The causes of this extinction event are still unknown. Possible causes include largest volcanic eruptions and global warming. Some scientists believe that there were several causes. They believe that a series of events caused the extinction
2、s. Scientists are working for better understand what really happened. In modern times, we human beings 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
3、 air makes people sick and afraid to get outside. Polluted water poisons our food supply. As a result, we never know which foods are safe to eat. Human beings can be not live in a poisoned environment. Therefore, pollution is a major threat to our existence. Humans need temperature to be in a comfor
4、table range. To be in a comfortable range means to be neither too hot nor too cold. With global warming, global temperatures are rising. As global temperatures rise, the polar icecaps will melt. As the polar icecaps melt, ocean levels will rise. Areas of some countries will soon be under water. Peop
5、le would be forced to relocated from flooded areas. In nature, even small changes can sometimes have large effects. Its difficult to predict whats going to happen. The entire ecosystem that we depend on is changing. Some of these changings are irreversible. Irreversible changes cannot be undone. Let
6、s hope the humans are smart enough to understand how the world is changing. With more understanding, we make better choices about what to do. We can face the challenge of the pollutions and global warming. We need to do this before its too late. This planet of earth is our only home and we need to p
7、rotect it. Unit 3-1 vocabularyLizard 蜥蜴Mammals are covered by hair or fur, have a backbone and warm-blooded. All mammals produce milk for the young. Reptiles are covered by scales, includes snakes, lizards and turtles. Reptiles have a backbone and are cold-blooded, which means they often rely on the
8、 external resources of heat. Birds are covered by feather and are warm blooded. Most of the birds can fly and many types of bird migrate great distances. Most insects such ants and bees have a small 3 parts body with 3 pairs of legs. Some insects, such as mosquitoes, spread diseases that cause the d
9、eaths of many humans. Unlike animals, plants get the energy that they need from the sun. Plants convert light energy along with carbon and water into chemical energy. Scales and rulers are used to measure weight and length. Units of weight includes kilograms and pounds and units of length includes c
10、entimeters and inches. These instruments are used to observe very large and very small objects. Telescopes are used by astronomers and microscopes are used by biologists and doctors. These appliances are used in the kitchens of almost every home. Stoves are used to heat food and refrigerators are us
11、ed to keep foods cool or cold. House tools like these, are used to build or repair things. Hammers are used to pound in the nails and screw drivers are used to turn a screw.Mammals include some of the most intelligent animals on earth, such as elephants and human beings.Mosquitoes cause the death of
12、 more human than any other animals. Rulers are used to measure lengthWe can use a telescope to see objects that are far way. Unit 3-1 dialogueDo you know what date is it today? What do you mean, its the special day?Oh, so you dont remember. Remember what? Whats the special?Its our anniversary. We st
13、arted dating a year ago today. Oh, really. Sorry. Just a minute, what do you think this is. Oh, its a necklace. Do you like it? Yes, I do. Its lovely. Especially the red heart. May I put it on?No, let me do it. So you did remember. Of course I remember. Its very special for both of us. I have someth
14、ing for you too. You do? Yes, but you have to wait until later. Oh, I cant wait. Tell me what is it. Can you guess what it is? Could you give me a h? We went there 3 months ago. Oh, you mean Alfredos. Yes, are you excited? You said you really like the food there. Yes, thats true. I also remembered t
15、he dessert. Do you?Yes, but lets not talk about that now. lets now view in the surprise. That restaurant looks nice. Yes, but it looks expensive. Lets go in and look at the menu. Wow, the menu looks great, especially the fish. Yes, it looks good but look at those prices. Lets try somewhere else. Som
16、etime its ok to spend a little money. Yes, but this price is a bit too high. Dont you think?Yes, they are a bit high. But dont you think it worth? Lets enjoy ourselves. Em, ok, if you put it that way. Lets see if we can take the table. Ive got you have a credit card. I sure hope the food is good. St
17、op worrying, lets just enjoy.Unit 3-2 ListeningQuick serve is a home repair company. It provides quick, reliable repair services to homes. Quick serve handles plumbing and electrical issues 24 hours a day. It also cleans the roofs, fixes internet connections and replaces broken windows. For a small
18、fee, customers subscribe to the service. Its main customers are elders, which means older people. Whenever customers have problems, they can call for help. There is also small charge for each service call. The company was established 5 years ago and is growing rapidly. It started in 1 city but its n
19、ow in 5 cites. The company plans to expand to 10 cities within the next 24 months. In each city, there is small central office in a low rent area of the city. The central office handles the businesses, advertising, payroll and billing. It also takes calls by customer either online or by telephone. I
20、t takes call 24 hours a day, 7 days a week. 60% of the companys employees work from their homes. When a customer calls into the central office, a service employee is contacted it. The service employee then contacts customer and sets up an employment. These employees are highly trained and provide ex
21、cellent services. 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 different parts of the country. They are not central located so its quick and easy for they to travel to customers home. Quick serve
22、 has an excellent reputation. Its prices are reasonable and it services are quick and efficient. The companys 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
23、 customers recommend quick serve to their friends. This kind of word-of-mouth advertising is very cost effective. Cost effect means that the results are good without paying a high price. In other word, quality service provides its own rewards to the company. The company take great pride in being hon
24、est with the 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 have confidence in the service provider. They don
25、t want to cheated. These people dont mind paying a reasonable fee for high quality service. High quality services should be rewarded. The company provides a range of service plans, each with a different subscription price. The least expensive service plan is called the basic plan. This plan provides
26、 non-emergency service with a very low service charge. The most expensive services plan is their VIP plan. The VIP plan provides emergency services 24 hours a day with no additional service charge. It also provides rebates for customers who dont call for any service during the year. In addition, qui
27、ck serve gives bonus points to customers for each year they subscribe. These bonuses can be used to buy new appliances such as stoves and refrigerators. If the business continues to grow, the owners may decide to take the company to public. This means that the public can buy shares of the company. I
28、t would then change from private-owned company to a public company. The owners believe that their business is successful and can expand around world. They also believe that taking their company public can make them rich. Unit 3-2 vocabularyBiology is study of life, including its structure and evolut
29、ion. Biology study how life survives and reproduces. Chemistry is the study of matter, including the structure of its atoms and molecules. Chemists study how various substances interact with each other.Astronomy is one of the oldest sciences. Astronomers study the structure and evolution of the universe, including the study of stars, planets and galaxies. Geologies is the study of structure of history of the earth and other planets. Geo
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