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Tet is a national and family festival. It is an occasion for every Vietnamese to have a good time while thinking about the last year and the next year. At Tet, spring fairs are organized, streets and public buildings are brightly decorated and almost all shops are crowded with people shopping for Tet. At home, every is tidied, special food is cooked,offerings of food, fresh water, flowers and betel are made on the family altar with burning joss- sticks scenting the air. First-footing is made when the lucky visitor comes and children are given lucky money wrapped in a red tiny envelope. Tet is also a time for peace and love. During Tet, children often behave well and friends, relatives and neighbors give each other best wishes for the new year.
An: Hello Manh , What are you doing ?
Manh : Oh , Hi An . I'm reading a magazine about tsunami .
An : What is tsunami ?
Manh : Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters. While tsunamis are often referred to as tidal waves, this name is discouraged by oceanographers because tides have little to do with these giant waves.
An : It sounds terrible .What is it cause ?
Manh: First , it causes many deaths . Since 1850 alone, tsunamis have been responsible for the loss of more than 430,000 lives. Second , the amount of energy and water contained in a huge tsunami can cause extreme destruction when it strikes land. And finally Tsunamis not only destroy human life, but have a devastating effect on insects, animals, plants, and natural resources. A tsunami changes the landscape. It uproots trees and plants and destroys animal habitats such as nesting sites for birds. Land animals are killed by drowning and sea animals are killed by pollution if dangerous chemicals are washed away into the sea, thus poisoning the marine life.
An : How can we to stop it ?
Manh : From my point of view, we need many factors to simulate Tsunami wave than we can find solution for this problem. One of this factor as Gobo A.E. mentioned above, also we need to know how many cycle per each period for example 10 years that happened and also the height of the wave when it attach the land. When we study deeply all factors then we can find solution such as we can made some gates in front of the coast lying horizontal in water when the level of water increase more then the normal this gate change its position to the vertical to crash the wave height and to reduce the damage on the land behind it.
An : That's true.
Every time we drive to school, use our heater or air conditioner, clean our windows, or even style our hair, we make choices that affect air pollution. These steps, as well as many others, are things we all can do to help reduce air pollution.
- Conserve energy – remember to turn off lights, computers, and electric appliances when not in use.
- Use energy efficient light bulbs and appliances.
- Participate in your local utility’s energy conservation programs.
- Limit driving by carpooling, using public transportation, biking and walking.
- Combine errands for fewer trips.
- Keep your automobile well tuned and maintained. Follow the manufacturer’s instructions on routine maintenance, such as changing the oil and filters, and checking tire pressure and wheel alignment.
- Avoid excessive idling of your automobile.
- Use electric or hand-powered lawn care equipment.
- Be careful not to spill gasoline when filling up your car or gasoline powered lawn and garden equipment.
- Run dishwashers and clothes washers only when full.
- Choose environmentally friendly cleaners.
- Use water-based or solvent free paints whenever possible and buy products that say "low VOC".
- Seal containers of household cleaners, workshop chemicals and solvents, and garden chemicals to prevent volatile organic compounds from evaporating into the air.
- Purchase and use low-polluting outboard marine engines and personal watercraft (4-stroke and direct fuel injection 2-stroke outboard marine engines).
- Advocate for emission reductions from power plants and more stringent national vehicle emission standards.
- Definition: Thermal pollution means a change in the water temperature.
- Causes:
+ Power station are one factor. They use water in the nearby lakes or rivers to cool their equipment, which heats up the water. Then they dump the hot water back into its source.
+ Thermal pollution may also happen due to the discharge of cold water from reservoirs into warm rivers.
- Effects: Most aquatic creatures need a certain temperature to survive. Warmer water has less oxygen in it, and this can harm fish populations. Besides, warmer water can cause harmful algal blooms. This can change the colour of the water like in the first picture and, more seriously, the algea poisons the fish. - Solution: In many places, they build cooling towers like in the second picture to cool down the water from power stations.