题目

将下列单词或词组填入空格。每空格限填一词，每个单词或词组只能填一次 A. where           B. In this way         C. Yet          D. improving         E. What’s more F. written           G. international        H. information   I. problems If you want to find out a piece of information about anything, the best place to search for it is Wikipedia. This online encyclopedia (百科全书) is ____51____ by thousands of people around the world. Anyone can add or change the information if he or she finds it not co已知集合则“”是“”的（ ）A.充分不必要条件 B.必要不充分条件C.充分必要条件 D.既不充分也不必要条件