please help answer parts B in the following picture im supposed to have a coneptual and internal ER model. The entities i have are: SALES REP, ORDER, CUSTOMER, TRUCK, DRIVER, ITEM and EMPLOYEE.

This is what i have so far

Office Supplies Inc. Office Supplies Inc. (OSI) sales office supplies to institutional buyers. It's saless representatives use the attached form to take orders. Customer account numbers on the form are unique. Customers have only one billing address. Each customer also has a designated contact person who is responsible for bill payment. The billing address of address or contact person of an existing customer. OSI offers free delivery service to its customers. Usually all deliveries are made within two business days of the order date. If a customer decides to use OSI's delivery service then the delivery address is filled in the order form. Sometimes a customer may not use the delivery service if he/she needs the supplies immediately. In such a case the customer is responsible for picking up the order from OSI's warehouse. All items in an order are delivered to the same address. OSI owns several trucks for delivering customer orders. Trucks have a vehicle number, license plate number, license expiration date, and inspection expiration date The same driver is always assigned to the same truck. OSI maintains information on items it sales. Each item type is identified by an item code and has a unit price. OSI also keeps a record of the number of units of each item type available for sale. OSI employs several employess. Each employee has a social security number, name, address, and phone number. Drivers are a type of employee. In addition to employee information, each driver also has a driver's license number and a license expiration date. Sales reps are also a type of employee. Sales reps have a salary and commission. All other employees have only a salary OSI wants to create an information system to manage its operational data. The OSI management has hired you as consultants for this project Requirements