First, multiple-choice questions.

The reciprocal of 1 -2012 is (a).

a、20 12 B、—20 12 C、 1/20 12 D、— 1/20 12

2. The absolute value of rational number is (d).

A positive number b negative number c non-positive number d non-negative number

3. Point A on the number axis means -3, and point B means 1, that is to say, the distance between point A and point B is (C).

a—3+ 1 B—3— 1 C 1—(—3)D 1—3

4. The following result is equal to 2 (b).

A buy -7 buy +5 buy B buy (-7)+(+5) buy C buy +7 buy +5 buy D buy (+).

5. The freezer temperature of the refrigerator is -6℃ and the indoor temperature is 20℃, so the indoor temperature is (C)℃ higher than the freezer temperature of the refrigerator.

A.-26 B. 14 C. 26 D.

6. If rational number A is the smallest positive integer and rational number B is the largest negative integer, then a+b is equal to (c).

A.2 B. —2 C. 0 D. 1

7. If a+b=0, then the numbers A and B must be (C).

A. both are equal to 0 b, one is positive and the other is negative. C.they are reciprocal. D. they are mutual.

Second, fill in the blanks.

1.-3 and (3) are reciprocal, and the absolute value itself is a (non-negative) number.

Please write down two numbers that are both negative and fractional (-1/2, -0.3).

3. Three fifths of the number is less than two fifths (-1/5).

4. The distance from the point representing -5 on the number axis to the origin is (5).

5. 丨 -2 丨 -6 丨 =(-4).

7.-2-3+5 is pronounced as (-2 minus 3 plus 5).

8. When X=(5/2), there is a minimum value of 2x-5, and the minimum value is (0).

Third, answer the question.

1. Based on the ground, the height of A is +2.5m..b is-17.8m, and C is-32.4m..

Q: (1) How much is A higher than B? (+2.5)-(17.8) = 20.3m.

(2) Where is A and C lower? How much lower?

A: C is low, low: (+2.5)-(-32.4)=34.9m,

If you are satisfied, please adopt it! !