Adult readers' borrowing cards are issued to China citizens who have reached the age of 14. They can use their ID card (remember the ID number) to pay a certain deposit (refund the card), fill in the reader registration form, and they can apply. The first card application is free. There are three kinds of deposits (optional): A: 100 yuan deposit, borrowing 3 books at a time, borrowing 2 1 day and renewing 2 1 day. B: 200 yuan deposit, five copies at a time, with a loan period of 2 1 day and a renewal of 2 1 day. C: 300 yuan deposit: seven books are borrowed at a time for a period of 2 1 day and renewed for 2 1 day. Children's library cards are issued to children under 14 years old. They can pay a certain deposit (refund the card) with their ID card or valid certificate (remember the ID number), fill in the reader registration form, and they can apply. The first card application is free. There are three kinds of deposits (optional). Answer: 50 yuan deposit, two books are borrowed at a time, with a loan period of 2 1 day and a renewal of 2 1 day. B: The deposit is B: 100 yuan, four books are borrowed at a time, with a loan period of 2 1 day and a renewal of 2 1 day.