помогите поставить предлоги at of between to on 1) i started school___the age___six 2) we have a lot___different subjects3)…

1) I started school at the age of six2) We have a lot of different subjects3) She's good at English4) Her pupils are between the ages of 12 and 165) My sister goes to a secondary school6) The teachers of the staff are very young and friendly