Topic content:
The following statement is correct: () A. If a is a rational number, then - a must be a negative number B. If a number is a rational number, then it is either a positive number or a negative number C. Positive numbers and negative numbers are collectively referred to as rational numbers D. Integers and fractions are collectively referred to as rational numbers
Best answer:
D
Answer analysis:
A、 If a is a rational number, then - a is not necessarily a negative number; Therefore, this option is wrong; B、 If a number is rational, it may be positive, negative or zero; Therefore, this option is wrong;
C、 Positive, negative and zero are called rational numbers; Therefore, this option is wrong;
D、 Integers and fractions are called rational numbers; So this option is correct. So choose D
Test core:
Definition of rational number: rational number is the general name of integer and fraction. All rational numbers can be transformed into fractions.