What do you mean by that?
C# doesn't support multiple inheritance like C++.
And I really don't understand your problem with "sealed".
Sealed is as it says : "sealed". Even me, as a non native english speaker can understand the word.
yes i mde so and now it brought to me other
question and useful instruments
I discover that class can be abstract and override
override I understood that one method use Parents same method but "abstract" is still a question for me
Yes and no, unless you fancy getting your educational reward (eg school certificate, diploma etc) to us, you need to learn for yourself, we dont do your work for you, we will help you with it. Reading something as simple as what keywords mean and so on, is something you really really need to do for yourself.. You're the one in education after all, not me. I did my bit, and how did I learn? I taught myself, other than its pointless me copy and pasting an answer or explaining it in my own words when you could read it and find it yourself in information you already have.
There are a half a true in your words
but like you know there are no such books that have explanation about each keyword
(and I have not just one book) and explanation there forward mostly for experience people and I think good people always will be glad to help each other.
that a reason I ask for questions here
But there are.. type it in and press F1 it tells you and has examples for nearly everything - failing that type it in google! Theres so much information there right at your fingers, if you cant be bothered to try looking for yourself, it seems wrong for you to be expecting others to do it for you.