问题
填空题
集合A={3，log2a}，B={a，b}，若A∩B={1}，则A∪B=______．
答案
∵由题意A∩B={1}，
∴得集合A和B中必定含有元素1，
即log2a=1，∴a=2，
∴A={3，1}，B={1，2}，
∴则A∪B={1，2，3}．
故答案为：{1，2，3，}．
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集合A={3，log2a}，B={a，b}，若A∩B={1}，则A∪B=______．
∵由题意A∩B={1}，
∴得集合A和B中必定含有元素1，
即log2a=1，∴a=2，
∴A={3，1}，B={1，2}，
∴则A∪B={1，2，3}．
故答案为：{1，2，3，}．
| 完形填空。 | |||
| One day a rich man met Tom. The rich man asked,“I hear you are very clever and 1 is difficult for you. Can you tell me why you are so clever?" Tom answered with 2 , "Oh, I am not clever. Instead, you are too foolish (愚蠢的)." The rich man became 3 . Tom said, “Sir, please 4 unhappy. If you don’t agree 5 what I said, now let me 6 you a very easy question: If you have a group of sheep, I send you 7 group. Then, you say, how many groups of sheep do you have?” "Why! That’s the easiest question in the world. One and one is two. 8 knows that. I have two groups of sheep, of course.” Tom laughed and laughed and said, “You are quite 9 , sir. Two groups of sheep put together is still one group. That’s the 10 question in the world, isn’t it? | |||
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