dlc general Knox quests...

Ok so here is my problem... I went online with a person who beat all of general knox's dlc quests then i went off and went back into single player when i looked in my quest log it was filled with quests that i havent done yet because i havent beatin them all yet and now i don't know which ones i can and can't do yet according to the quest line and areas that havent been unlocked yet.