Answer: from different ways
Explanation:
Answer:
It's the Inner Core
Explanation:
It is the innermost layer of planet earth & composed primary of Iron and Nickel , This is because through the geological time Iron and Nickel which are heavier elements sank down and formed the core.
And plus, the Crust (The land you stand on when you walk outside) is made of soil and rock, and the Mantle (Under the Crust) is hot liquid like lava.
'Climatic variations' and 'Human activities' can be regarded as the two main causes of desertification. removal of the natural vegetation cover（by taking too much fuel wood）, agricultural activities in the vulnerable ecosystems of arid and semi-arid areas, which are thus strained beyond their capacity.
Is 195 countries in the world
