I keep coming across these (I know they have not all been assigned yet, but they are BASIC), so here are some quick answers; look up the reasons in the Rules for Writers (RW)!
--The man WHO, not the man THAT.
--Quotation mark placement, e.g., "dogs," not "dogs",
--, and in a series, e.g., "dogs, cats, and mice."
--Spell out most numbers; spell out "percent."
--Use parallel structure!
--No run-ons!
--No comma splices!
--The mysterious "They." Highlight every use of this in your paper. Is it clear who "they" are? If not, edit!
--Dangerous passive voice, e.g., "Human trafficking IS CONSIDERED the fastest growing crime." Use active voice, e.g., "Many authoritative researchers deem human trafficking to be the fastest growing crime."