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Nemokami pratybu atsakymai

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DIDŽIAUSIA PRATYBŲ ATSAKYMŲ SVETAINĖ!

Tai didžiausia Lietuvoje nemokamų pratybų atsakymų svetainė. Moksleivis užsukęs čia, negali aklai nusirašyti, atvykęs čia jis turi tiesiog pasitikrinti jau atliktus namų darbus!

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The Last Continent

Today I’d like to tell about the land where probably you had never been.

When astronauts view the earth from space, says the book Antarctica: The Last Continent, the most distinctive feature of our planet is the ice sheet of Antarctica. It “radiates light like a great white lantern across the bottom of the world” the astronauts reported.

Why Antarctica is a unique continent?

Antarctica is the most isolated continent in the world. It is supremely beautiful and pristine bbut brutally inhospitable. It is the windiest, coldest place on earth, yet it is singularly delicate and sensitive. It has less precipitation than any other continent, but it’s ice represents 70 percent of the planet’s fresh water. With an average thickness of some 2200 meters, the ice makes Antarctica earth’s highest continent, averaging 2300 meters above sea level.

In fact, Antarctica has been likened to a vast natural laboratory for studying the earth and its atmosphere as well as global eenvironmental changes, including those related to human activities. Antarctica is also earth’s fifth-largest continent, yet it has no permanent residents larger than a one-centimeter wingless midge, a type of fly.

As you venture into Antarctica’s interior, you see fewer and ffewer signs of life, especially when you reach the areas called dry valleys. Covering some 3000 square kilometres, these polar deserts are mostly set high in the Transantarctic Mountains – a chain of ranges spanning the continent and rising in places to over 4300 meters. Icy gales whistle through the dry valleys and quickly whip away any snow that might fall. Scientists believe these valleys to be the nearest earthly equivalent to the surface of Mars. Hence, they were deemed a suitable venue for testing space equipment before launching the Viking mission to Mars.

Yet, even the dry valleys host life. Inside porous rocks, in tiny air pockets, live exceptionally hardy forms of bacteria, algae, and fungi. They survive on tthe barest trace of moisture. Outside, their surreal world is one of stark rock formations called ventifacts, whose bizarre shape and high sheen are the result of countless centuries of Antarctica’s unremitting winds.

Additionally, an absence of land predators combined with a bountiful marine food supply make the Antarctic coast a summer haven for wildlife. In the Antarctica was probably the largest congregation of wildlife that existed in the world. Here lives an abundance of seals, penguins, and whales.

Antarctica is the oonly continent on earth to be completely governed by an international agreement. Called the Antarctic Treaty, the agreement was signed by 12 governments and entered into force on June 23, 1961. Since then, the number of participating nations has grown to over 40. The treaty’s objective is “to ensure, in the interest of all mankind, that Antarctica shall continue forever to be used exclusively for peaceful purposes and shall not become the scene or object of international discord.”

The continent and its dependent marine ecosystems are designated as a “natural reserve devoted to peace and science.” Military activities, weapons testing, and the disposal of nuclear wastes are prohibited. Even sled dogs are banned.

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Superkami pratybų atsakymai!