Who killed Goliath?😀🤪

A teacher came in to class & asked a question
Teacher: who killed Goliath?
Student1: i wasnt in school on dat day
Student2:it's not me 
Student3: i don't know
Teacher got angry & went to HM office & told him dat de students not know who killed Goliath ,so de HM followed de teacher to classroom. The following conversation 
HM:who killed Goliath?
Class: we are not de ones
HM: if you don't tell me who killed Goliath you'll see fire 2day
Class: we don't know
HM: turned to de teacher & asked are you sure Goliath was killed by someone from dis class?
De teacher fainted