Answer in one sentence only

1) What is Subsidiary Books ?
2) What is a Cash Book ?
3) State the meaning of ‘Contra entry’.
4) State the meaning of imprest system of Petty Cash Book.
5) Which transactions are recorded in Purchase Book ?
6) Which sales are recorded in Sales Book ?
7) Which transactions are recorded in the Journal Proper ?
8) Who is a Petty Cashier ?