I had this question I think it’s gamma rays
The type of stream valley likely to form in a mountainous area is a V- shaped valley. This is a narrow valley that has a profile giving the impression of the letter V. This kind of valley is characterized by steeply sloping sides. It results from a stream eroding downward, a process referred to as downcutting. V - shaped valleys form in mountains or highland areas where streams are in their youthful stage and are flowing rapidly down steep slopes.
Regeneration is the ability to gain something back again.
