tìm x biết a) 5(x+3)-2x(3+x)=0 b) 4x(x-2004)-x+2004=0 c) (x+1)²=x+1

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Exercise 8. Choose the correct answers to complete the passage.        Three ways everyone can help make the Earth a greener place is to reduce, reuse, and recycle!        When people reduce it means they are using (1)________ of something. This allows us tocreate less waste. Turning off the faucet when we brush our teeth is a simple way to reduce. This is a small action that prevents us from wasting (2)________.        Another small action people can take is to reuse things we already have. Taking bagsto the store (3)________ we shop for food is one way to reuse them. Using both (4)________ ofpiece of paper before getting a new one is another way to reuse.        (5)________ is when new materials are created from old ones. Paper, plastic, and metalare all materials that can be recycled. Things like newspapers, soda cans, and plastic bags can all be turned (6)________ new objects if we take the time to recycle them! 1.   a. much       b. more       c. little       d. less 2.   a. energy       b. electricity       c. water       d. time 3.   a. when       b. what       c. how       d. while 4.   a. ways       b. sides       c. parts       d. points 5.   a. Reusing       b. Reducing       c. Recycling       d. Reacting 6.   a. out       b. up       c. down       d. into Exercise 9. Read the passage then choose the correct answers. Green Cities        What makes a city green? It’s a huge challenge for cities to be earth-friendly. Not only do they have lots of people, buildings, traffic, trash, and air pollution, but they also consume more than half of the world’s energy.        Many cities in the world have taken up the challenge to be earth-friendly. Look at what some of these cities have done:        Reykjavik, Iceland, is run entirely on green energy. Its transit system uses hydrogen buses and most of its buildings use non-polluting energy sources like geothermal and hydroelectricity.        Malmo and Stockholm in Sweden are noted for their green spaces and parks and for successfully cleaning up their water and air.        Portland, Oregon, was one of the first American cities to focus on earth-friendly transit with light-rail and bike paths to encourage people to leave their cars at home.        Curitiba, Brazil, uses unique green methods for maintenance. Their grass parks are trimmed by sheep!        Vancouver, British Columbia, uses wind, solar, and water energy to generate power. Nearly all of the city is powered by clean hydroelectricity. 1.   In what country is Malmo?        a. Brazil       b.Spain       c.Sweden       d.Iceland 2.   How much of the world’s energy is consumed by cities?        a. one quarter       b. one and a half       c. more than half       d.all 3.   Which city is run entirely on green energy?        a. Reykjavik       b.Seattle       c.Stockholm       d.       Portland 4.   How are the buses powered in Reykjavik?        a. diesel fuel       b.hydrogen       c.unleaded gasoline      d.geothermal 5.   How does the grass get cut in the parks of Curitiba?        a. They use push mowers.       b. Children stomp on it.        c. People trim it off.       d. Sheep graze on it. 6.   None of Vancouver is powered by hydroelectricity.        a. True       b.False       c.No information 7.   Portland, Oregon was one of the first US cities to focus on earth-friendly transit.        a. True       b. False       c. No information

Exercise 6. Complete the passage with the words from the box. freely      used        schoolwork         more       robots        transmits      health    since        I have had my robot for 3 years now, and it has helped me enormously with my (1)________. I can’t go to school because I have a (2)________ condition. So I send my robot to school in my place. The robot (3)________ information to me in real time and I can ask it to perform a number of functions. It asks and responds to questions from teachers, can move (4)________ around the school, and it even interacts with my classmates. I am really happy with it and my grades have improved dramatically (5)________ I have had it.        Although it was pretty difficult to get (6)________ to using the robot at first, I realise I am really lucky to have him. I was reading in the paper the other day that a lot of kids want (7)________ to learn or play with, or help them with their chores. I suppose a lot (8)________ people will have robots in the future as this type of technology continues to develop at a frightening pace. Exercise 7. Read the passage, then do the tasks.                      Earth Day is a birthday! Just like a birthday is a special day to celebrate a person, Earth Day is a special day that celebrates the Earth. It is a day to remember to take care of our planet.        Earth Day was born on April 22,1970, in San Francisco, California. It is now the largest, most celebrated environmental event worldwide. Every year, many countries around the world join together in the celebration of Earth Day on April 22nd. On Earth Day, people celebrate by doing things that help to protect the environment. Some things people do to help the Earth are: turn off the lights to conserve energy, plant trees, recycle, and pick up garbage in their communities.        You don’t have to wait for Earth Day though, you can help the environment every day! A.   Decide whether the following statements are True (T) or False (F). 1.   The first Earth Day was celebrated around the world. 2.   Earth Day is a day to take care of our planet, Earth. 3.   A few countries celebrate Earth Day. 4.   On Earth Day, people do some good things that help the planet. 5.   Turning lights off is a way to save energy. B.   Answer the questions. 1.   Where was Earth Day started?               2.   On what day is Earth Day celebrated?               3.   What can people do to help the Earth?