Water!

When you're thirsty, you drink water.

When you want to take a shower, you turn on a faucet.

But did you ever think about where all the water comes from?

One reason mountains are important is that they provide fresh water

for over half of all the people in the world.

That's about three-and-a-half billion people!

Can you imagine howmuch water is used by all those people?

When the sunwarms water in riversand oceans,

the liquid is transformed into water vapor that rises into the air.

When enough water vapor cools, it condenses, and small drops of water are formed.

The drops of water turn into clouds.

In the clouds, small drops of water join to make larger drops.

When those drops become too heavy, they are released as rain or snow.

Some rain soaks into the ground, and some of the rain runs over the ground into streams,rivers, lakes, and the ocean.

This process is called the water cycle.

Mountains can affect the water cycle.

The size and shape of a mountain pushes the water vapor up toward the mountaintop.

When water drops fall on mountains, most of the water is stored as snow, and as ice in glaciers.

When the snow melts in the spring, the water flows down the slopes into streams, waterfalls, and rivers.

Mountains are effective in storing water and are sometimes called the "water towers" of the world.

All of the big rivers on Earth start in the mountains.

For example, in India, the Ganges River starts in the Himalayan mountain range

and flows for 2,500 kilometers into the Bay of Bengal and the Indian Ocean.

Another example is the Rio Grande, which begins in the Rocky Mountains in the United States

and flows all the way down to the Gulf of Mexico.

Animals!

Mountains are also important because they provide homes to many animals that don't exist

anywhere else on Earth.

You can find mountain gorillas in the mountains of East Africa

and special bears called spectacled bears in the Andes.

There are also snow leopards in the Himalayas.

Mount Cameroon is a mountain that is also one of Africa's largest active volcanoes,

rising to more than 4,000 meters at its peak.

It has 210 different species of birds and 70 species of butterflies.

Mountains are home to many amazing animals and birds.

Unfortunately, some of these animals are becoming rare.

This is happening because people are taking more land

and using more resources, such as water and wood.

They are building farms and roads in the mountains.

This means animals have less space to make their homes and find food.

Food!

Did you know that 80 percent of the food we eat comes from just 20 types of plants?

Six of these plants are found in the mountains!

Do you like French fries?

Well, guess what?

Potatoes first came from the Andes, the world's longest mountain range,

which stretches 7,000 kilometers through South America.

Today, farmers in the Andes grow 2,000 different types of potatoes.

In the mountains of Nepal, about 2,000 different types of rice are farmed.

Corn is found in the Sierra Mountains of Mexico.

And the best quality tea and coffee are grown at an altitude of about 1,500 meters.

Farmers sometimes build terraces into steep mountainsides and hills to grow crops

and help control the flow of water.

The terraces made by Inca Indians 500 years ago

are still used by farmers in the Andes Mountains in Peru.

Remember how water from rain and snow flows down mountains?

With rich soil and a lot of water,

mountain valleys are often good places to grow fruits,vegetables, and other crops.