The long straight line is a scratch on the negative; may have been caused in the camera or during processing. Since it's intermittent, I'm going to guess that it was in camera and the film wasn't wound evenly (thus giving the small gap in the streak).
All the other marks look like dust that was on the negatives when they were scanned. If the dust got on the film while it was wet from processing, it'll be in the exact same places on the prints as well, and you won't be able to get rid of it. If it got on after the film had dried, it should brush or blow off for a re-scan.