The error in the sentence is a squinting modifier.
Explanation:
The original sentence can be revised as "We kept in the closet an extra rack for the stove", a squinting modifier is a misplaced modifier, this common error creates an ambiguous meaning in the sentence, the original sentence "We kept an extra rack for the stove in the closet." might be understood that the stove is in the closet, while the revised one clearly says that what is in the closet is just the rack.
"sport's" is incorrect because there is an <span>apostrophe s which means that it's supposed to be possessive. Sport is not possessing anything. So it should instead be sports.
<em><u>the fraction is the </u></em><em><u>form written by in the form of </u></em><em><u>p</u></em><em><u>/</u></em><em><u>q</u></em><em><u> </u></em>