Crossword Puzzle Four forerunner

Clue: Four forerunner

Opening foursome (ABCD with 4 letters)
Two foursomes (e.g. OCTAD with 5 letters)
Fourth-rate grade (DEE with 3 letters)
Speedskater who won the fourth season of "Dancing With the Stars" (OHNO with 4 letters)
NRC forerunner (AEC with 3 letters)
Fourth line of verse (PLUSSOMECASHTOVOTETWICE with 23 letters)
Hacky Sack's forerunner (BEANBAG with 7 letters)
Roped by all fours (HOGTIED with 7 letters)
F's forerunners (ABCDE with 5 letters)
Animal captured in Hercules' fourth labor (BOAR with 4 letters)