题目8单选题
设集合A={1,2},B={a,b,c},C={c,d},则A×(B∩C)=()A. {(c,1),(2,c)}B. {(1,c),(2,c)}C. {(c,1),(c,2) }D. {(1,c),(c,2)}
题目10单选题
设S={1,2,3,4},A上的关系R={〈1,2〉,〈2,1〉,〈2,3〉,〈3,4〉} 则R <img src="https://tihai-oss-cloud.itihey.com/img/79510045f5d8ffe3307af2ffd62b5c93.png">R=( )A. {〈1,1〉,〈1,3〉,〈2,2〉,〈2,4〉}B. {〈1,2〉,〈2,1〉,〈2,3〉,〈3,4〉}C. {〈2,1〉,〈1,2〉,〈3,2〉,〈4,3〉}D. {〈1,2〉,〈2,3〉,〈3,4〉,〈2,4〉}