1. The viruses spread through E-mails CDS Websites All the above 3. Which one is not a server level threat? CGI threats Database threats Malicious code All the above 7. Portals primarily generate revenue in all of the following ways except: * Charging advertisers for ad placement. Collecting transaction fees Sales of goods. Charging subscription fees. 6. What floods a Web site with so many requests for service that it slows down or crashes? Computer virus Worm Denial-of-service attack None of the above 19. Clickstream factors include * Number of pages viewed Number of past purchases Number of products viewed All the above