Writers/producers/directors..please do your homework. Gunpowder was invented in 850AD, which was 300 years later after Wei. So there should not be fireworks used in signalling or in military warfare... audiences nowadays are not stupid any more. So Writers/producers/directors..you guys need to step up.  No more rubbish please. Looks like many writers nowadays lack of ideas or even do their research. For example, someone sick must vomit blood or when someone hear suprising news must drop something. Looks like these directors must be using same old and outdated textbooks.