Well, unacceptable means not acceptable, so you can use it in the sentence,"You only finished half of your homework; this is unacceptable."
"The fistfight at the school board meeting was unacceptable behavior by public officials." "His essay was found to be unacceptable, and he had to rewrite it." "Adding nonsense answers to WikiAnswers is an unacceptable practice."
The result to my unacceptable behavior in school is retribution.
Swearing at a teacher is unacceptable.
The judge set out to reprove the actions of the defendant as an example of unacceptable behavior .
the horse raced past the barn fell
An acceptable way to use credit is to buy groceries and clothes. An unacceptable way is to buy a tank or Australia with it.
"These" is the plural of "this," so you would use it to indicate what you're writing about. For instance, you could say "these results are unacceptable" to show that you don't mean just any results, but certain results specifically.
"That behavior is completely unacceptable and utterly disgraceful."
Unacceptable is an adjective to mean something that is inappropriate or of low quality. Examples: "Profanity is unacceptable language at school." "The quality of this lumber is unacceptable."
"His behavior was absolutely unacceptable and completely inappropriate." This sentence contains evaluative modifiers "absolutely unacceptable" and "completely inappropriate" expressing strong disapproval.
If by 'this structure' we're talking about sentence structure, then what is unacceptable is the ambiguity as regards what the actual subject of the sentence is. The ambiguity has to do with the fact that 'this structure' can also mean the structure of a building or other physical object; if that's the case, then this question could be trashed with the comment, "Not enough information to answer."
Your tardiness is unacceptable Bobby! Go to the office right this second! I hope that's what your question was.