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Saturday, August 30, 2008

Why don’t newly-born babies have teeth?

When a baby leaves the mother’s womb to live in the outside world, his small stomach does not immediately adapt to a mixed diet. This is why the baby needs his milk. Teeth are not needed for this type of food because the baby does not have to chew. Indeed, they would be in the way as the baby has to suck his food into his mouth. And it would not be very comfortable for the mother to breast-feed a baby who had a mouthful of teeth.
As the baby grows, teeth begin to appear in the gums of his mouth. This stage is called teething, It can be a little painful for the baby and he may cry when his teeth come through. When the baby has teeth he can start to eat solid foods
t is very important to look after a child’s teeth right from the start. This is one reason why babies need milk as the calcium in it helps to make teeth grow healthy and strong.

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Thursday, August 21, 2008

What is taste?

Taste is one of the five senses, the others being sight, smell, touch hearing. Our chief organ of taste is the tongue, which is covered with tiny cells or taste buds. These react to different taste and send messages to the brain
You may be surprised to learn that there are in fact only four kinds of taste; sweet, sour, salty and bitter. All the flavours we know are a combination of these four.
Just as there are four kinds of taste, so there are four kinds of taste bud, and these are situated in different areas of the tongue. Only the centre of the tongue has no buds at all, as you will see if you put a little salt on the middle of your tongue. Experiments with other flavours to find the areas of taste buds on your tongue, and then see how placing an ice cube on your tongue affects your sense of taste.

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What is an albino?


An albino is a person or an animal without any colour at all in their skin except red caused by blood vessels. This is quite rare, and means that person has very white skin, white hair and pink or red looking eyes. The red colour appears because there are lots of blood vessels in the eye. Albinos live all over the world – there are albino people in Africa, where rest of their family is the colour you would expect. As well as being striking to look at, albinos also have problems if they live in sunny countries. Because they have no colour in their skin, they also have little or no protection against the harmful rays of the sun, and can burn very easily unless proper care is taken. Albino also have no colour in their eyes, which means that there is little or no protection against strong light, so many albinos have to wear dark glasses for most of the time.

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Monday, August 11, 2008

Why do soldiers wear Khaki?

Soldiers wear khaki for camouflage, or course, to ensure that they blend with their background and make them lees easily spotted by their enemies.
In early times camouflage was not so important to soldiers; fighting at that time was usually hand to hand, and distinctive uniforms were necessary so that the combatants could discriminated between friend and foe. The uniforms were as colorful as possible and were covered with feathers, ribbons and to other decorations to give the fighting men a sense of unity, a feeling of belonging to, and being a part of their own regiment.
But with the invention of the breech-loading gun and long-range artillery, camouflage became very important indeed, as the British soldiers fighting in the American War of Independence found to their cost. Many of the Americans had no uniform as such, and wore their usual hunting shirts, whose neutral colour gave them good protection. The British soldiers, in their red coats and white breeches, presented perfect targets, and were unable to melt into the landscape.
In the 1840s Lieutenant Harry Lumsden was forming a regiment cavalry and infantry in northern India, and was given permission to arm and dress his men as he whished. Since their duties would involve skirmishes with the natives he decided that his men should wear with the natives he decided that his men should wear uniforms the color of the local ground, so that they would be inconspicuous, and cloth specially dyed locally. It was called Kahki after the Urdu word for dusty, and when Lumsden’s regiment went into action in 1849 they were known as the ‘Mudlarks”.
The success of the Khaki camouflage led to all British soldiers being issued with Khaki uniform when they were posted overseas, though colours charged slightly in accordance with the surrounding countryside.
When the First World War started in 1914 some cavalry regiments were their traditional colourful uniforms, but they soon changed to Khaki, the colour of the med in the trenches and the dust of the roads they had to travel.
Today soldiers all over the world dress in Khaki, glad to the protection it affords them. The bright, colourful uniforms that once glamourized war have disappeared.

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Thursday, August 7, 2008

Why do we need water?

Very simply – because our bodies are about two thirds water. The human body contains about eleven gallons of water, and as we get rid of our body water by sweating and other means, we must replace it. The water in our bodies is not the same as ordinary drinking water, or course. There are many chemicals in it, which the body needs to grow and repair itself, and the water moves these substances around inside the body so that each part gets the amount it needs. Although on some days you may not drink as much as on others, you take in water from the solid things you eat - vegetables, fruit, meat and bread are about a third water themselves.
Blood is mainly water. About a gallon of all water in our bodies is in the blood, but that level always remains the same, no matter how much you drink.

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Tuesday, August 5, 2008

What would we do without Coal?

Coal is something which we all need in some way or other. We need coal to produce heat and light for our homes and offices; our industry needs coal to provide many commercial and household goods to export all over the world.
Different types of coal are often found in a coalfield. There are ‘coking coals’, for instance which, when mined, aren’t used for home consumption but are valuable for the belts furnace of a steel works. Then there is anthracite, a hard kind of coal which burns with a very intense heat.
Coal is still mined today by men going down into the earth and risking their lives to bring the coal from the seams up to the surface. Despite a great many new safety measures mining is still a difficult and dangerous job. At least the practice of taking children to work down the mine shafts has ceased now, although pit ponies are sued to pull loads of coal under ground.
There are quite a few mines in Britain, mostly in Wales. Scotland and North-East England. A world famous mining area is the of the Rhur valley in Western Germany.

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Saturday, August 2, 2008

What would we do without Wool?

Wool has kept us warm since ancient times when man first domesticated sheep, and even in this age of synthetic fibers wool still remains a firm favourite with most of us. Britain, especially, has a lot sheep grazing on the hills of Scotland, Wales and Ireland, and has a thriving wool industry.
Britain was very important when it came to wool-producing in the Middle Ages, and a sack of wool became a status symbol of wealth, hence the Lord Chancellor’s seat in the House of the Lords becoming known as the wool sack. All in all, the sheep population of the world is about 970,000,000!
When shorn, the sheep’s fleece is matted and oily and unfit for spinning, so the fleece must be washed and ‘carded’ before going on to the next process. Once spun, the wool goes on to be woven into the woollen clothes and rugs, carpets, etc., we are familiar with in the shops. In the middle Ages the Flemish were celebrated weavers; these days Bradford and Leeds are well known for their fine weaving.

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Inventions, science, useful topics for students.