CONTOH2 EXPLANATION TEXT

WHY SUMMER DAYLIGHT IS LONGER THAN WINTER DAYLIGHT

         In the summer, the amount of daylight that we get is more than we get in winter. This is not because as much people think we are closer to the sun but because of the tilt of the earth.

                The earth is actually closer to the sun in winter than it is in summer but you would be forgiven for thinking that this can not be true after looking out of your window on a cold and frosty morning. It seems strange that as the earth get closer to the sun during its orbit then the amount of daylight that we get decrease. But that is the case. It is the tilt of the earth that determine the amount of daylight that we get and so the length of time that for us the sun is above the horizon.

  (Taken from: www.ictteachers.co.uk)

    Analysis of The explanation of WHY SUMMER DAYLIGHT IS LONGER THAN WINTER DAYLIGHT

        Generic Structure Analysis :
General statement; stating the phenomenon which daylight in summer is longer than in winter.

Sequenced Explanation; it is the tilt of the earth that determines the amount of daylight not the distance of the earth from the sun.

Language Feature Analysis
Focusing generic participant; daylight.
Using chronological connection; then, so, but.
Using passive voice; you would be forgiven.
Using present tense; the earth is actually closer to the sun.

Tsunami

                   The term of “tsunami” comes from the Japanese which means harbour ("tsu") and wave ("nami"). A tsunami is a series of waves generated when water in a lake or a sea is rapidly displaced on a massive scale.

                 A tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Such large vertical movements of the earth's crust can occur at plate boundaries.

                Subduction of earthquakes are particularly effective in generating tsunami, and occur where denser oceanic plates slip under continental plates.

              As the displaced water mass moves under the influence of gravity to regain its equilibrium, it radiates across the ocean like ripples on a pond.

                Tsunami always bring great damage. Most of the damage is caused by the huge mass of water behind the initial wave front, as the height of the sea keeps rising fast and floods powerfully into the coastal area.

  (simplified from www.panda.org)

How Roman Roads were Built

                  The system of roads for mobility has been begun early decades. It was started since the Roman Empire conquered the world. The roads in Roman era were known as the best construction.

                      The Romans built roads are for the purpose of mobility, especially for the army. Having the best road, the army could march from one place to another. They built the roads as straight as possible, so that the army could take the shortest route.

                      It is interesting to know how the roads were built, which some of them are still in use today. First, the Romans builders would clear the ground of rocks and trees. Then they dug a trench where the road was to go and filled it with big stones. Next, they put in big stones, pebbles, cement and sand which they packed down to make a firm base. After that, they added another layer of cement mixed with broken tiles. On top of that rough construction, then they put paving stones to make the flat surface. These stones were cut so that they fitted together tightly. As the finishing touch, kerb stones were put at each sides of the road to hold in the paving stones. It was also used to make a channel for the water to run away.

  (Partly taken from: www.teachingideas.co.uk)

CANCER

                    What is cancer? It is actually a group of more than one hundred separate diseases. Most of us are fear from cancer It is reasonable because next to heart disease, cancer is the second leading cause of death.

                 Cancer cells come from normal cells because of mutations of DNA. Those mutations can occur spontaneously. The mutations may be also induced by other factors such as: nuclear and electromagnetic radiation, viruses, bacteria and fungi, parasites, heat, chemicals in the air, water and food, mechanical cell-level injury, free radicals, evolution and ageing of DNA, etc. All such factors can produce mutations that may start cancer.

                         Cancer cells are formed continuously in the organism. It is estimated that there are about 10,000 cancer cells at any given time in a healthy person. Why do some result in macroscopic-level cancers and some do not? First, not all damaged cells can multiply and many of them die quickly. Second, those which potentially divide and form cancer are effectively destroyed by the mechanisms available to the immune system.   Therefore cancer develops if the immune system is not working properly or the amount of cells produced is too great for the immune system to eliminate.

  (Simplified from:www.digital-recordings.com/publ/cancer.html)

How Earthquakes Happen

        Earthquake is one of the most destroying natural disasters. Unluckily it often happens in several regions. Recently a horrible earthquake has shaken West Sumatra. It has brought great damages. Why did it occur? Do you know how an earthquake happens?

Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves. It make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. They don't just slide smoothly. The rocks are still pushing against each other, but not moving. After a while, the rocks break because of all the pressure that's built up. When the rocks break, the earthquake occurs.

During the earthquake and afterward, the plates or blocks of rock start moving, and they continue to move until they get stuck again. The spot underground where the rock breaks is called the focus of the earthquake. The place right above the focus is called the epicenter of the earthquake.

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Mainly taken from: www.geo.mtu.edu/UPSeis/why.html

How do seasons happen?

Seasons come to us regularly. We have probably noticed that it gets warmer in summer or dry season while it get colder in the winter or wet season. However do we know how these seasons change?

Seasons happen and change every year. This happens because the earth tilts back and forth as it goes around the sun. During the summer, the earth tilts toward the sun. It makes half of the earth hotter. this condition is what we call summer. During the other half of the year, the earth tilts away from the sun. As a result, it makes that half of the earth cooler. This cool condition is then what we call winter.

The different parts of the world have the same season at different times. In the northern half of the world , winter happens during the months of December, January and February. The regions are such North America and Europe. In the other hand, the southern half of the world have winter during the months of June, July and August. The regions are like South America and Australia. How does this difference happen? The same season happens at different times because the top and bottom halves of the earth tilt away from the sun at different times.

  Source: kidscientist.com/5/why-do-seasons-happen

How does Rain Happen?

        Rain is the primary source of fresh water for most areas of the world, providing suitable conditions for diverse ecosystems, as well as water for hydroelectric power plants and crop irrigation.
The phenomenon of rain is actually a water circle. The concept of the water cycle involves the sun heating the Earth's surface water and causing the surface water to evaporate. The water vapor rises into the Earth's atmosphere. The water in the atmosphere cools and condenses into liquid droplets. The droplets grow until they are heavy and fall to the earth as precipitation which can be in the form of rain or snow.
However, not all rain reaches the surface. Some evaporates while falling through dry air. This is called Virga, a phenomenon which is often seen in hot, dry desert regions.

  Source:http://mypages.iit.edu/~smart/abduima/lesson2.htm