つつある => to be doing; to be in the process of doing ~ N2
つつある => In the middle of A; in the process of A N2
Time, Situation
いつかの ... => Previously N4
Time
あかつきには => After A then B N1
Time, Situation
ひとつには…ためである => Partly because of ... N3
Cause, reason
~且つ(かつ) => and N1
Line up, list
いつも => always; usually; habitually N5
~つい      => accidentally; unintentionally; by mistake N3
Regret
つつ => while; even though; despite ~ N2
あるいは~あるいは~ => or, either N3
Line up, list
いつしか => before one knows N2
Accept, agree
いつか => Since when (Don't know) N4
Time