please use scenario to answer questions below (1-3)

In the Web-based Online shopping system, customers can request to purchase one or more items from the supplier. The customer provides personal details, such as address and credit card information. This information is stored in a customer account. If the credit card is valid, then a delivery order is created and sent to the supplier. The supplier checks the available inventory, confirms the order, and enters a planned shipping date. When the order is shipped, the customer is notified and the customer's credit card account is charged. 1) List the software high-level functions (10 points) 2) Model the system use-case diagram (20 points) 3) For the same use-case diagram, develop a class diagram (20 points)