“Do you know tablet pc?”Or” Do you have a htc phone?” If I ask you a question,you must laugh at me .As a matter of fact, it is indeed a bad question for me asking such a retarded question. You even may say that the person who doesn’t know computer had been going to see the God. But do you know what a LED flashlight is?
Bur if I ask another interesting question which is closely correlated with computer you will feel ashamed for the words you just said. That is “Do you know LED flashlight?”