听力原文： When a savings account is opened in a bank, the depositor must sign a deposit agreement. By signing agreement, the depositor agrees to abide by the rules and regulations of the bank. At this time, a passbook may be given to the depositor. This is a small book in which the bank teller enters the date and amount of each deposit or withdrawal and initials the entry. The passbook is to be presented at the bank or mailed to the bank along with a deposit or withdrawal slip each time money is deposited or withdrawn from the account. An alternative practice for depositing or withdrawing money from a savings account is to give the depositor a small register for recording deposits and withdrawals and a pad of deposit withdrawal rotors. This procedure eliminates the use of the passbook.
24. What is the purpose of signing a deposit agreement？
25.What does a depositor do with a passbook？
26.What is the aim of a small register and a pad of deposit withdrawal forms？
(24)

A. To follow the bank's rules and regulations.
B. To have the right to make full use of the bank's facilities.
C. To open an account in the bank.
D. To protect the depositor's interest.