Поставить глагол-сказуемое одного предложения из текста во все временные формы (present, past, future) групп continuous и perfect в страдательном залоге on the average students attend school approximately six hours a day. !

On the average school is attended by students approximately six hours a day. Continuous:
1) Present: is being attended
 2) Past: was being attended
3) Future –––

Perfect:
1) Present: has been attended
2) Past: had been attended
3) Future – will have been attended