Тема: Вода (Виды водных объектов, круговорот воды, разрушающая и созидающая роль воды)
Water
Water is a ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all forms of life. Water is the only substance on our planet that can be found in all 3 states at the same time (slide 1)
Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products.
Water cycle
The sun, which drives the water cycle (slide 2), heats water in the oceans. Water evaporates as vapor into the air. (slide 3) Ice and snow can sublimate directly into water vapor. Evapotranspiration is water transpired from plants and evaporated from the soil. Rising air currents take the vapor up into the atmosphere where cooler temperatures cause it to condense into clouds (slide 4). 
Air currents move clouds around the globe, cloud particles collide, grow, and fall out of the sky as precipitation (slide 5). 
Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years. Snowpacks can thaw and melt, and the melted water flows over land as snowmelt. Most precipitation falls back into the oceans or onto land, where the precipitation flows over the ground as surface runoff (slide 6). 
A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans.
Oceans
It’s rather difficult to answer the question about the quantity of oceans. The unity and continuity of the World Ocean, with relatively free interchange among its parts, is of fundamental importance to oceanography. It is divided into a number of principal oceanic areas that are delimited by the continents and various oceanographic features: these divisions are the Atlantic Ocean, Arctic Ocean (sometimes considered a sea of the Atlantic), Indian Ocean, Pacific Ocean, and Southern Ocean.
* The Pacific Ocean (slide 7)., the largest of the oceans, also reaches northward from the Southern Ocean to the Arctic Ocean. It spans the gap between Australia, Asia, the Americas and Oceania. The Pacific Ocean meets the Atlantic south of South America at Cape Horn.
* The Atlantic Ocean (slide 8), the second largest, extends from the Southern Ocean between South America, Africa, North America and Europe, to the Arctic Ocean. The Atlantic meets the Indian Ocean south of Africa at Cape Agulhas.
* The Indian Ocean (slide 9) extends northward from the Southern Ocean to India, between Africa and Australia. The Indian Ocean joins the Pacific Ocean to the east, near Australia.
* The Southern Ocean (slide 10) is the ocean surrounding Antarctica, dominated by the Antarctic Circumpolar Current, generally the ocean south of sixty degrees south latitude. The Southern Ocean is partially covered in sea ice, the extent of which varies according to the season. The Southern Ocean is the second smallest of the five named oceans.
* The Arctic Ocean (slide 11) is the smallest of the five. It joins the Atlantic near Greenland and Iceland, and joins the Pacific at the Bering Strait. It overlies the North Pole, touching North America in the Western hemisphere and Scandinavia and Asia in the Eastern hemisphere. The Arctic Ocean is partially covered in sea ice, the extent of which varies according to the season. Some authorities do not consider the Arctic Ocean a bona fide ocean, because it is largely surrounded by land with only limited exchange of water with the other oceans. Consequently, it is considered by some to be a sea of the Atlantic, referred to as the Arctic Mediterranean Sea or Arctic Sea.
