The purpose of extending the set of natural numbers to the set of integers is to make it closed under ______ operation
举一反三
- Among the four sets of natural numbers, integers, rational numbers and real numbers, which one includes the others? A: The set of natural numbers B: The set of integers C: The set of rational numbers D: The set of real numbers
- Which of the following is equivalent? A: The division relation on the set of integers B: On the set of rational numbers, the relation of multiplication equal to 1 C: rank relationship D: Logical equivalence of propositional formula
- Which of the following is equivalent? A: The division relation on the set of integers B: On the set of rational numbers, the relation of multiplication equal to 1 C: rank relationship D: Logical equivalence of propositional formula
- One set of numbers consists of consecutive integers and the least number is 3.How many numbers are there in the set (1)The average of all the numbers in the set is 6; (2)The number of integers is one more than the range of the set. A: 条件(1)充分，但条件(2)不充分． B: 条件(2)充分，但条件(1)不充分． C: 条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分． D: 条件(1)充分，条件(2)也充分． E: (E) 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
- If the sum of a set of ten different positive prime numbers is an even number, which of the following prime numbers CANNOT be in the set ？（） A: 2 B: 3 C: 5 D: 7 E: 11