I found these riddles , can anyone help me figure it out?

[Joy]

1. I am as cold as death, and not breathing air.
Never thirsty, but ever drinking
Covered in mail, but never clinking
What am I?

Answer is Fish - this one is actually from "Riddles in the Dark" - The Hobbit

4. Until I am mesured,
I am not known.
Yet how you miss me,
When I have flown.
What am I?

Answer is Time

7. What can run but never walks,
Has a mouth but never talks,
Has a bed but never sleeps?
What am I?

Answer is River

These are all I know right now. I might figure out more later.

[ March 05, 2002: Message edited by: Joy ]