Deserts may seem lifeless，but in fact many kinds of living things have developed special ways to live in the difficult environments.
    So what is a desert？Deserts cover more than one-fifth of the Earth's land area.A place that receives less than 25cm of rain every year is considered a desert.Only about 20% of deserts are covered by sand.Some have mountains，rocks or lakes.Some are even among the planet's last remaining areas of total wilderness（荒野）.Yet more than one billion people，one-sixth of the Earth's population，actually live in desert areas.
    The largest hot desert in the world，northern Africa's Sahara，even reached temperatures of up to 56℃.But some deserts are always cold，like the Gobi Desert in Asia and the Antarctic Ice Sheet （南極冰蓋），which is the world's coldest.The coldest recorded temperature there is -53℃.The driest desert Chile's Atacama Desert has parts that receive less than 2mm of rain a year.
    People living in desert areas have to live in tents.They mainly use camels as their means of transportation.As for food，they usually eat some vegetables and meat，but not so fresh.Desert animals have their own ways to keep cool and use less water.Camels can go for weeks without water.Many desert animals，such as desert foxes，only come out to find food when the sun goes down.Most desert animals can't spend much of their time on the surface of the ground because of its high temperature during the day.Desert plants may have to live without fresh water for years at a time.Some grow long roots to get water from deep in the earth.Others have roots that spread out a long way so they can take in the rain as soon as it falls，such as cacti（仙人掌）.
    Life is hard in the desert.Luckily，they've got used to the life there.

	Facts	*They cover more than 20% of the（1） land area land area in the world. *There are over 1 billion people living in desert areas.
	（2） Famous deserts in the world Famous deserts in the world	*Hot desert --- the Sahara *Cold desert --- the Antarctic Ice Sheet *Dry desert --- the Atacama Desert
	Special ways to live there	*For people： They live in tents and ride camels when they go out. *For animals： They like to go out at night or stay（3） underground underground . *（4） For plants For plants ： Their roots are very long or spread a long way to get water.
	Conclusion	（5） Although Although life is hard in the desert，they've got used to it there.