If there's a function "Question-Answer", it is possible as that to implement? For example: The user has sent the question InputMode like me to answer it?

Yes, it is possible. The question can be retrieved from user's via input node which should be followed by variable node to choose the path of answers depending on what a user has answered to a question.

I can add a template of a question-answer episode to your bot. Please do point me to your bot link at onsequel.com.

I've gone ahead and added a Quiz template to your bot as an episode. Please go through this quiz template episode and let me know if you need any further help in creating a Question-Answer bot.

And all found, thank you

Great!