1. The following statement is true ()

① Rational numbers are either integers or fractions; ② Rational numbers are either positive or negative;

③ An integer is either positive or negative; (4) a score is either positive or negative.

A. 1

2.a and B are rational numbers, and the positions of their corresponding points on the number axis are shown in the following figure:

a 0 b

Put a, -A, b and -B () in descending order.

A.-b