Помогите сделать предложение в special questions 1)Они продали свое оборудование

1. the sold their equipment on timewhat did they sell on time?what did they do on time?when did they sell on time?who sold equipment on time?

2. they buy power equipment every monthwho buy power equipment every month?what do they buy every month?what do they do every month?when do they buy equipment?how often do they buy equipment?what equipment do they buy every month?

3. yesterday I was at school.where was I yesterday?when was I at school?who was at school yesterday?what did I do yesterday?