(1) brian spent all of sunday cleaning his room. (2) first, he picked up the junk on the floor because that was the majority of the mess. (3) it was those small finishing touches that made the room sparkle. (4) second, he made his bed and folded his clothes. (5) at that point, the room was shaping up. (6) third, he organized his books and video games into alphabetical order on the shelves, which was fairly simple since they were no longer scattered around the room. (7) fourth, he dusted the shelves and desk. (8) finally, brian cleaned his windows and mirror. (9) although he spent all day cleaning his room, he went to bed relaxed and comfortable.
after which numbered sentence in the paragraph should the following sentence appear?

slightly less important than dusting the furniture was vacuuming the carpet, which he did next.
sentence 8
sentence 1
sentence 7
sentence 5