A person who whispers during your talk.
A person who challenges the facts you presented.
A person who asks an irrelevant question.
A person who interrupts you before you are ready to answer questions.
A person who asks a question that is related to the topic, but is not within your area of knowledge.
Politely tell them that you don't really deal with that aspect of the situaiton.
Tell them you will come back to their point later.
Give evidence for your statements and don't respond emotionally.
Ignore them.
Politely redirect the conversation.
