21. By saying “... owners of well over half of all World Wide Web sites have set up home without fitting locks to their doors" (Lines 3-4, Para. 2), the author means that _____. (A) those happy times appear still to be with us (B) there simply wasn't any crime to worry about (C) many sites are not well-protected (D) hackers try out tricks on an Internet site without actually breaking in

22. SATAN, a program designed by Dan Fanner can be used ____________. (A) to investigate the security of Internet sites (B) to improve the security of the Internet system (C) to prevent hackers from breaking into websites (D) to download useful programs and information