Kamis, 15 September 2011

Contoh Teks Explanation

The Process of Rain
Water in the earth is kept in many places like the ocean, the ocean, the river and the lake. But don't be wrong, the plants leaves and the land also kept water.
Each day, this water will evaporate with help of the sun. The process where water evaporates from plants is called transpiration. Afterwards the vapour will experience the process of condensation where the vapour will condense and turn into a cloud. The form of the cloud always changes according to weather conditions.
The clouds will move to different locations with the help of wind that bellows vertically or horizontally. The movement of the vertical wind results in the cloud forming big 'lumps'. After that, the wind increases the size of the cloud and each cloud will overlap. Finally the cloud will reach the atmosphere that has a lower temperature. Here the particles of water and ice is formed.
Eventually, the wind can not support the weight of the cloud and so the cloud that is full with water will experience a process called precipitation or the process where rain or hail falls to earth.

How a Spider’s Web Forms
A Spider web looks delicate but it is very strong. It can hold 4000 times a spider’s weight. But how does it form.
First the spider spins a thread of silk. The thread gets blown over to a branch by teh wind. Then she makes another two threads and makes a Y shape. Next she makes more threads and they look like spokes off a wheel. Then the spider goes in a spiral, out and back in, sits in the middle and waits for food.
This is how a web is formed.
Venus Flytrap
The Venus Flytrap is an extraordinary plant. It is a carnivorous (flesh eating) plant which can digest flies and other insects.
When the ‘trap’ is open, it looks like a large seashell with sharp, spiky ‘teeth’. It has bright colours and a beautiful scent.
Insects are attracted to the plant because of its vibrant colours and its sweet-scented nectar. The insects land on small ‘trigger’ hairs of the trap and this pressure causes the trap to close. If the insect is too small, the chamber will not close, because there is not enough pressure. Once the trap has swallowed an insect it takes ten days to diggest it.
The Venus Flytrap prefers tropical weather and so it is found in places like South America. It is often used by people to catch the annoying insects that fly around their houses. In my opinion it’s very useful plant!
The Picher of Death
You may have heard of a plant called the Picher of Death. As you can probably tell by its name, it kills and eats insects. If you want to know how, read on!
To catch flies and other insects, this plant needs a bait and a trap. The bait in this case in nectar. The trap is the cup or ‘pitcher’ shaped leaves which have short hairs at the top to give the insect a sure foothold, but slippery hairs pointing downwards, so it can’t escape once it falls in. the other part of the trap is a digestive fluid inside the cup.
How it catches the insect is really quite simple. First the insect is attracted by the nectar. Then it slips on the smooth inner surface of the plant. Next it is forced downwards by the slippery hairs. Then it falls into the digestive fluid and is drowned.
An interesting fact about this plant is that the pitcher leaves can grow to the size of a fully grown adult’s hand.
How It Works
Frogs are delightful creatures. Our country is home to more than 220 named species and they can be found in almost any Australian landscape. Most frogs lay eggs on land or in the water. Then, after the eggs hatch,
Tadpoles enter the water for two weeks to six months, depending on the temperature, before emerging as froglet (baby frog). Not all frogs do this. The hip~ pocket frog is a very interesting example of parental care. After the female hip-pocket frog has spawned, the male will lie on her eggs and about eight tadpoles wriggle up into each pocket where they grow into baby frogs. Australia’s two species of gastric brooding frogs are even more amazing. They swallow their fertilised eggs and hatch the tadpoles in their stomachs. Six weeks later the _froglets emerge from their mother’s mouth.
PETROLEUM PRODUCT
Petroleum products, such as gasoline, kerosene, home heating oil, residual fuel oil and lubricating oils, come from one source - crude oil found below the earth’s surface, as well as under large bodies of water, from a few hundred feet below the surface to as deep as 25,000 feet into the earth’s interior. Sometimes crude oil is secured by drilling a hole through the earth, but more dry holes are drilled than those producing oil. Pressure at the source or pumping forces crude oil to the surface.
Crude oil welts flow at varying rates, from ten to thousands of barrels per hour. Petroleum products vary greatly in physical appearance: thin, thick, transparent, or opaque. Their chemical composition is made up of only two elements: carbon and hydrogen, which form compounds called hydrocarbons. Other chemical elements found in union with the hydrocarbons are few and are classified as impurities. Trace elements are also found, but these are of such minute quantities that they are disregarded. The combination of carbon and hydrogen forms many thousands of compounds, which are possible because of the various positions, and varied joining of these two atoms in the hydrocarbon molecule.
The various petroleum products are refined from the crude oil by heating and condensing the vapours. These products are the so-chatted tight oils, such as gasoline, kerosene and distillate oil. The residue remaining after the tight oils are distilled is known as heavy or residual fuel oil and is used mostly for burning under boilers. Additional complicated refining processes rearrange the chemical structure of the hydrocarbons to produce other products, some of which are used to upgrade and increase the octane rating of various types of gasoline.
Early Dams
Dams have been built on rivers and streams all over the world for thousands of years. In the Egyptian desert cast of the Nile River are the remains of a masonry dam that probably dates back to 2500 BC. Other ancient darns have been found in present day Iraq, Syria, and Arabia. Most of these dams were used for collecting and storing water for irrigating the fields in the dry desert regions.
Early dams were built with rocks, earth, and wood. These dams worked fairly well unless the pressure of the water became too great, or they were overtopped by high flows of water; Then the dam would be washed away. Gradually men learned how to design dams that could withstand great pressure. New materials were added ’to strengthen the darns.

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