Question

The vegetation become dense where the rainfall is heavier give reason for this question

Answer 1

Vegetation  is dense in the areas that have heavy rainfall because rainfall makes the land more fertile and supplies an adequate amount of water needed for cultivating. The problem  with semiarid regions is that when human use them for agriculture, the loss of natural vegetation  can cause  the areas to become deserts.

Answer 2

vegetation become denser in these places because these places gets lot of rain and plants grow day by day there is no need of Man to do any work here