Answer the following questions. 1 、 What is a credit system? 2 、 What do businesses use a credit system for? 3 、 How long have people been buying things on credit? 4 、 What are the two types of credit cards? 5 、 What are the differences between them? 6 、 Why do you usually need to apply for a credit card at a bank? 7 、 How often does a credit company send the customer a statement of purchases? 8 、 What are the advantages of having a credit card? 9 、 What is the main disadvantage of using a credit card?