A database is needed for maintaining the websites related to courses taught at a university. The characteristics of a Web page include a unique ID, a title, its URL, and the number of times that the web page has been accessed. A course Web page has an associated base page and a base Web page serves as the base of all of the Web pages associated with the course. A Web page can be accessed through the link on another page. A Web page can display many graphics and a graphic can be displayed by many Web pages. The characteristics of a graphic include a unique ID, the name of the graphic, the format of the image, such as 'gif, jpg' or 'bmp, and the directory in which the graphic image is located. A Web page can provide ftp links to several courseware files and a courseware file must be linked to by some Web page(s). The characteristics of courseware include a unique ID, a description of the course material, the directory in which the file material is located and a category describing the type of course material, such as 'P' for publication, 'N' for notes. Design an ER diagram for the above. Specify key attributes of each entity type and structural constraints on each relationship type. Specify any additional assumptions. A database is needed for maintaining the websites related to courses taught at a university. The characteristics of a Web page include a unique ID, a title, its URL, and the number of times that the web page has been accessed. A course Web page has an associated base page and a base Web page serves as the base of all of the Web pages associated with the course. A Web page can be accessed through the link on another page. A Web page can display many graphics and a graphic can be displayed by many Web pages. The characteristics of a graphic include a unique ID, the name of the graphic, the format of the image, such as 'gif, jpg' or 'bmp, and the directory in which the graphic image is located. A Web page can provide ftp links to several courseware files and a courseware file must be linked to by some Web page(s). The characteristics of courseware include a unique ID, a description of the course material, the directory in which the file material is located and a category describing the type of course material, such as 'P' for publication, 'N' for notes. Design an ER diagram for the above. Specify key attributes of each entity type and structural constraints on each relationship type. Specify any additional assumptions