Causes of attrition?

The formation of numerous, closely spaced rills due to the uneven removal of surface soil by streamlets of running water. Also known as rilling; rill wash; rillwork.

Proximate: What triggered the immediate response of an animal? Ultimate: how did it benefit the species?

Insecurity? If there's one person who about insecurity, its me. I spent my early childhood incredibly insecure. And up until now, I still know lots of other people who are stuck in that STAGE. There...

is a cause of the phenomenon (such as a disease or weather)

A headace is cause by a boy named hasan alabaca. he is so dumb and lound.:]