'Surely' in the Bible

Surely it is futile to spread a net in plain sight of any bird,

The one who puts up security for a stranger will surely have trouble, but whoever avoids shaking hands will be secure.

When you gaze upon riches, they are gone, for they surely make wings for themselves, and fly off into the sky like an eagle!

For surely there is a future, and your hope will not be cut off.

Surely I am more brutish than any other human being, and I do not have human understanding;