use '?' for JOKER (blank)

From letters O, B, S, E, R, V, A, N, C, E  I made following words

10 letter words

observance[17]

8 letter words

verbenas[13], conserve[13], converse[13], obscener[12], seaborne[10]

7 letter words

verbena[12], beavers[12], caverns[12], cravens[12], bravoes[12], observe[12], obverse[12], verbose[12], corvees[12], absence[11], beacons[11], obscene[11], boraces[11], carbons[11], corbans[11], oversea[10], careens[9], caserne[9], recanes[9], aerobes[9], acerose[9], boranes[9], canoers[9], coarsen[9], corneas[9], narcose[9], boreens[9], enrobes[9], encores[9], necrose[9], arenose[7]

6 letter words

vocabs[13], beaver[11], carven[11], cavern[11], craven[11], corvee[11], aboves[11], covens[11], braves[11], carves[11], cavers[11], craves[11], breves[11], bravos[11], bevors[11], corves[11], covers[11], beacon[10], carbon[10], corban[10], bacons[10], bancos[10], braces[10], cabers[10], rebecs[10], carbos[10], carobs[10], cobras[10], broncs[10], veenas[9], venose[9], averse[9], reaves[9], ravens[9], nerves[9], soever[9], sovran[9], careen[8], recane[8], aerobe[8], ocreae[8], borane[8], canoer[8], cornea[8], boreen[8], enrobe[8], encore[8], encase[8], seance[8], seneca[8], beanos[8], canoes[8], oceans[8], crease[8], caners[8], casern[8], cranes[8], nacres[8], rances[8], censer[8], screen[8], secern[8], boreas[8], coarse[8], barons[8], acorns[8], narcos[8], racons[8], boners[8], censor[8], crones[8], recons[8], arenes[6], ranees[6], arseno[6], reason[6], senora[6]

5 letter words

bacon[9], banco[9], acerb[9], brace[9], caber[9], rebec[9], carbo[9], carob[9], cobra[9], bronc[9], carbs[9], crabs[9], beano[7], canoe[7], ocean[7], caner[7], crane[7], nacre[7], rance[7], ocrea[7], baron[7], acorn[7], narco[7], racon[7], boner[7], borne[7], crone[7], recon[7], cease[7], banes[7], beans[7], nabes[7], acnes[7], canes[7], scena[7], benes[7], cense[7], scene[7], obese[7], canso[7], bones[7], ebons[7], cones[7], scone[7], bares[7], baser[7], bears[7], braes[7], saber[7], sabre[7], acres[7], cares[7], carse[7], escar[7], races[7], scare[7], serac[7], beers[7], brees[7], ceres[7], scree[7], barns[7], brans[7], carns[7], narcs[7], brens[7], boars[7], boras[7], orcas[7], bores[7], brose[7], robes[7], sober[7], arene[5], ranee[5], aeons[5], erase[5], saree[5], earns[5], nares[5], nears[5], saner[5], snare[5], ernes[5], sneer[5], arose[5]