题目

51. George Washington was born in 1732 in a rich family in _______ is now the state of Virginia. A. which          B. where              C. that             D. what 答案：D设集合A{2，3，5}，则集合A的个数为        ；如果集合A中至多有一个奇数，则这样的集合A共有        个.