Помогите пожалуйста составить 5 вопросов к предложению . Our teacher was telling us about Africa when the bell rang

1) Was your teacher  telling you about Africa when the bell rang? 2) What was  your teacher telling about when the bell rang? 3) Was your teacher  telling you about Africa when the bell rang, wasn't he? 4) Was your teacher  telling you about Africa  or America when the bell rang?  5) What was your teacher doing when the bell rang?