1。 当A=(X/x=x), B=(x/x不等于x), and C=(x/x is the element of x) 我们可以问9 种membership questions of these three: A is the member of A, A is the member of B , A is the member of C , B is the member of A , B is the member of B, B is the member of C , C is ........... can anyone give me the answer of these 9 membership questions? www.ddhw.com www.ddhw.com
|