What has one letter and starts with an E?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

What month of the year has 28 days?

I make two people out of one. What am I?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

I have an eye but still cannot see.

Who am I?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?