What kind of a teacher would back away from showing and explaining a technical question to his/her student when asked by the student.

Maybe a teacher who doesn't actually know the answer and is afraid of admitting that they need to find out more information before being able to deliver a good explanation?

Maybe a teacher who realizes that the answer to the question will not lead the student in the right direction.

One of the first things students have to learn is what questions to ask. There are many other things for which you could demand specific information, but where the answers can only be misleading, because they focus attention in the wrong areas.

While I agree with you, Anonymous, I'd think that a good teacher would be able to explain to the student why they aren't ready yet to delve into the subject, or why it's better to focus on a more appropriate area first (often so as to develop the skills and understanding needed to tackle the asked-about area).

Well since we dont know what "back away" means exactly, I take it from the context that the instructor did not explain to the student that the question would not help them at their current level.

Some teachers do not know how to handle unexpected questions.

Example: after looking at quickstep on this page I asked two instructors if they could show me the basic step, I made it clear I didnt want to learn just see what it looked like from up close.
Answer 1: "Quickstep is stupid."
Answer 2: "I haven't actually practiced quickstep in months. Let me try... sorry no I dont think I can show it out of the blue"

I really respect the second answer.

I also found "You are rushing too far ahead lets stick to the simple things for now." or "We'll get to that when you are ready for it" I was told at other occasions (waltz mostly) acceptable.

So as long as they give a good answer, even if it doesnt answer the question I think they can show their high quality. Noone can know everything all the time.
The problem is when instructors are too insecure to admit that they too arent perfect.

well in my case i asked my teacher to show me what cbm excatly is and she goes well dont be so technical because it is a natural thing for your body to do it when you are turning. well i can agree on that but i know for sure that i am not doing it correctly. what shoudl i do..just keep quite and continue with her or insist that an explanation and a feel of cbm will do good to my dancing?

If you think this will help you then insist. She should adapt her teaching style to the needs of the individual student. If you need to "get technical" then that is what she should do to teach you.
Most teachers/instructors, not only in dancing, get used to one style of teaching. The good teacher is the one that tries to adapt when they realise their normal style doesnt have the desired result.

You don't say how long you've been dancing, but if you're a beginner, you probably shouldn't worry about it yet.

If you don't know what it is, how do you know that you're doing it wrong?

If something feels wrong to you or you aren't sure you are moving correctly when you turn, ask her specifically about what you are doing while you show her how you are now doing it. Tht way, she can address your actual dancing, which is more important than being shown a specific technical element in isolation.

i have been dancing for 4 years now and am very comfortable with all figures. I did speak to my teacher of what i am looking for in my classes like technique and concepts, but i feel i have to really try hasrd to get something out of her. I know she knows it but i feel like unless i dont mention it , she wont teach

Are you saying that she doesn't teach you any technique at all? I mean things like how to use your feet, what your posture should be, how you should be using different parts of your body when you move, how to lead, etc.? Or does she show you what to do but just not talk about it in coneptual terms?

Some people learn through movement, rather than through ideas. Your teacher may be that kind of person, and she may feel that talking about concepts is unnecessary, if she's getting you to progress with her current methods. If so, and you like your teacher, you may want to try to get technical concepts through another means to complement what she teaches you, like technique books or videos.

But if you are saying that all she teaches you is figures, limited to where your feet should be on what count, them maybe it's time to consider another, more technically-oriented teacher.