Bantu Mwuara

321) the family of indigenous languages ​​of central and southern part of the African continent. Northern border languages ​​B. passes approximately 5 ° c. sh. Cameroon volcano from the west to the lake . Albert W. , and then deviates to the south, reaching the 2 ° S . sh. near the shore of the Indian Ocean . In the southwestern part of the continent languages ​​B. border Bushmen and Hottentots languages ​​prevalent in southern Angola and South-West . Africa. Total number of speaking the language B. – about 83 million people . ( 1967 estimate ) .
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Snow on the fields …

34“Snow on the fields – the bread in the bins .”

This old Russian proverb very precisely defines the role of snow in agriculture. And last year’s snow ! It is known that the temperature of the soil, its moisture content , chemical composition, structure , saturation microorganisms to a large extent depend on the thickness of winter snow covers it and its properties .
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From snowflakes to ice 2

36In the spring of 1944 in Moscow fell flakes up to 10 centimeters in diameter, they were like little slowly circling saucer . Such a snowflake falling on the black pavement, gave a big white spot , like a snowball thrown . In Siberia observed flakes diameter of 30 centimeters. They were like a slowly falling from the sky caps of white fluffy fur. High , loose drifts grew easy on the eyes.
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From snowflakes to ice

37In 1611, the German astronomer Kepler published the essay ” New Year’s gift , or hexagonal snow .” There he speaks of forms snowflakes , ponders the question: “Why is snow hexagons ? ” And he responds : ” The thing is this , I have not opened .” In our time , although it has since passed more than three centuries , experts say that they have to repeat this answer Kepler .
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What is the weight and how much weight snowflake all the snow!

38“White fluffy snow in the air spinning and falling to the ground softly falls.” And it seems there is nothing weightless tiny snowflakes. Fall into the hands – not even feel it. Weighs about a milligram, rarely – 2 … 3 milligrams. Fine mesh snowflakes hanging in the air like snowflakes all fall and fall. And they have millions, billions … In a few hours the vast expanses of land may be under a fluffy blanket of snow. How much snow weighs now? “Pukhov” blanket like a herd heaviest weights that could affect the Earth’s rotation rate.
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Why snow slippery 2

29Important role in the speed of movement on snow plays a material runners and structure of snow. The friction coefficient also depends on the length of the sliding surface. So, when tested steel skis found that with the increase of its length from 1.0 to 1.7 metres friction is reduced by two-thirds. The longer the sliding surface, the more the friction and the more heat is allocated on the contacts runners with snow grains, and this improves “lubricant and reduces the amount of friction. It would seem clear: ski to do long and glide faster… But here shall assume the role of the pressure. If it is not enough friction on the snow may increase. Especially at low pressures and temperatures of snow around 0 C.
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Why snow slippery

31Sliding on the morning snow,
My darling friend, share the run
Impatient horse…

A. Pushkin.

One of the very important properties of snow is that it slippery. Sledge path and fast and easy, and convenient. To slide on snow – move around in a sleigh, it is necessary to spend 10 times less energy than to move on wheels.
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