Given two different character sets (A and B), which of the following must be true for A to be considered a strict superset of B? (Choose all that apply.)
A. A must contain all of the characters defined in B.
B. A must be Unicode.
C. The encoded values in A must match the encoded values in B for all characters defined in B.
D. A must be a multibyte character set.
E. The encoded values in A must match the encoded values in B for all numeric and alphabetic characters in B.
A strict superset must contain all characters found in the other character set and have matching encoded values for those characters.
原文：http://www.cnblogs.com/Babylon/p/7833765.html