lankeela - // when on programmes they pretend to knock on a door and the person opens it as though they are surprised but there are obviously cameras already inside. Classic case is Long Lost Families - Davina and Nick go to someone's house as though they have just pulled up outside. We know they do many takes for this sort of thing so why do they keep up the pretence? //
It's simple dramatic licence, it goes on all the time on television and in film.
When the guy breaks out of prison after being inside for twenty years and can drive a car smoothly as though he drove it this morning.
When people always answer the phone, or the door, they're never on the loo or in the bath.
When people never say Umm, or Err, or What was I saying?
Have you ever seen anyone in a soap cough or sneeze unless its part of the plotline?
As for burping - that simply never happens.
But we accept these things, even though we know they are nonsense, because that's how the medium works.