They Are Leaving The Things That Belong To Them At That Place

I've always thought that if I was a teacher, on the first day of class I would do a little exercise to separate the wheat from the chaff, as they say.  It would be a dictation of a simple sentence.  It is a sentence that consists of only five words.  Five common, heavily utilized English words.  Three of these words are homophones that a large percentage of people for some weird reason simply cannot use correctly.  Commonly, they use one of these three homophones for all occurrences of any of these three words in writing.  Here is the sentence:   "They're leaving their things there."

How many of them would begin scratching their heads as they looked at the sentence they had scrawled on their papers?  "There leaving there things there."  How many would find that sentence perfectly acceptable?