Hugging the trees inorder to save them from being cut down became famous. This movement is known as the ________movement.

The gas essential for the growth of plants.

The invention of _________ helped man to progress.

The organisms in a biosphere are ________ on one another.

The upper most part of the lithosphere forms a thin layer of ___________.

Which zone is called the 'living world'?

Grassland is a __________ ecosystem.

The term lithosphere means ___________.

The different sources of water such as oceans, seas, bays, lakes, rivers etc form the ___________.

The _________ prevents the sun's harmful rays from reaching the earth's surface.