Lets try to solve the following question.
Never one to mince his words, Antonio was the perfect ________________ ; even an outright fabrication was delivered with aplomb.

A) Hack
B) Idler
C) Benefactor
D) Dissembler
E) Official

It is a tough Text Completion because there is a good chance that most of us wouldn't know the meaning of those highlighted words- mince & aplomb. There are already two big hurdles to cross to solve the text completion successfully and we haven't even read the options yet. So what happens when you face this kind of questions when you do not understand the meaning of 1 or 2 words? You cannot comprehend the entire meaning of the sentence. Is it unsolvable then? You might as well guess one of the options and move on.But No!! It is still quite solvable. Lets see how we can use our logical prowess to solve this problem.

Strategy

The best possible steps you can take now are the following ones
1. Break down the sentence.
2. Focus on the words you know- Ignore the ones you don't.
3. Come up with your own word.

First clue can be the word fabrication. Most of us should know that it means a lie, a kind of deception. So from the sentence structure it may seem that he can even deliver an outright lie with "Aplomb". So we are getting a hint of what aplomb can mean. It may mean that he can lie with extreme coolness or calmness. Now it feels we are making some progress.

Next step is to investigate the first part of the sentence. From the overall tone of the sentence we can try to understand whether the word in the gap will be a negative one or a positive one. So what do we know? That he is a liar, who can lie maybe with calm and composure. So the word in the blank cannot be a positive one.
It has to be a negative one. Now lets evaluate the answer choices.

Evaluating Options

A) Hack- You may not know what it means. But it certainly has a negative connotation about it.
B) Idler- One who idles. Not really a liar. So it cannot be the answer.
C) Benefactor- The root word "ben" means goood. So it cannot be a negative word.
D) Dissembler- No idea what it means. So we will come back later.
E) Official- Not really relevant here. So it cannot be the answer.

So after this strategy we are only left with two viable options- A & D. Not bad huh!!!
Ok now we are gonna evaluate our last two options and get something meaningful out of it.

Hack - What other words you may know about hack? Maybe after going through tons of vocabulary you may know the word "hackneyed". It means boring ,unoriginal, trite. Its not really 'quite where we should be going right?

Dissembler- So now that you have an idea that hack is not really the word we are going for then you have only one option left. At this point you have to guess and just move on. But at least it was a 50-50.

Answer

Fortunately in this case Dissembler is the right answer. It comes from "Semblance", which means facial expression. Adding "dis" to it means concealing or falsifying your expressions thus lying.