What is blank verse how do i determine if a line is blank verse

What is blank verse?! how do i determine if a line is blank verse?

I know blank verse is when it doesn't rhyme, but like if you are given a few lines and have to decipher which one is blank verse, how would you go about this?

for example:

which of these would be considered blank verse?

"And passing even into my purer mind."
or
"The Landscape with the quiet of the sky"
or
"Five years have past; five summers with the length"
or
"The day is come when I again repose"

which one would be considered blank verse? and why?