1. Multiple choice questions (3 points for each question, * * * 24 points)

The value of 1. Equal to ()

The third century BC.

2. In the number-1.4 14, π, 3. , 2+, 3.2 122 1 …, 3. 14, the number of irrational numbers is ().

A.5 B.2 C.3 D.4

3. The following conclusions are known: ① Only irrational numbers can be represented on the number axis; ② Any irrational number can be represented by a point on the number axis; ③ Real numbers correspond to points on the number axis one by one; ④ Rational numbers are infinite and irrational numbers are limited. The correct conclusion is ().

A.①② B.②③ C.③④ D.②③④

4. The following calculation is correct ()

a、B、C、D、

5. In the following statement, () is incorrect.

The arithmetic square root of A 3 is the square root of B 3 is.

C-3 is the arithmetic square root of D. -3 is the cube root of D.

6. If both A and B are real numbers and satisfy │ A-2 │+= 0, then the value of B-A is

A. 2b. 0c-2d. None of the above is true.

7. If it is -3, the value range of is ().

A.> 3 B. ≥3 C.