1. Use UML to model the software architecture of an online trusted payment system. The system users are buyer, seller, payer, and security trustee. There are many e-payment selections available. The buyers may be consumers, corporations, or organizations. The sellers may be merchants, service providers, and others. The payers may be banks, financial services, credit card companies, etc. The trustee may be a security service, transaction auditing company, etc. The system supports payment selection, security services, transaction protection, and process flow management. The system administrator is also a special system user. 2. Use UML to model the nationwide chain motel online reservation system. The system provides the reservation request service for room selection, date selection, reservation deposit handling, reservation cancellation, and reservation confirmation. The system also provides online information about location, direction, facility, motel photos, etc.