First of all, choose one carefully. Only one answer to each question is correct. Please look at the four options before making a decision! (3 points for each question, ***36 points)

The title is123455678911112.

answer

1, the following statement is correct (b)

A positive and negative numbers are collectively called rational numbers; B 0 is an integer, but not a positive number;

C 0 is the smallest rational number; D 0 is the smallest positive number.

2. The number represented by-a must be (D).

Negative number; B negative integer; C positive or negative number; None of the above conclusions are correct.

3. There are four statements as follows: ① The antonyms of rational numbers are all positive numbers; ② The absolute values of rational numbers are all positive numbers; ③ The absolute value of rational number is not positive; ④ The number with the smallest absolute value is 0. The correct one is (b)

A 0 B 1 C 2 D 3

4, the sum of two numbers is less than each addend, then (b)

A One of these two numbers must be 0; B these two numbers must be two negative numbers;

C these two numbers are positive and negative, and the absolute value of negative number is larger;

The signs of these two numbers d cannot be determined.

5. The square of the sum of the reciprocal of19 and the reciprocal of 13 is equal to (c).

a 1 16 B 14 C 16D 9

6, if the sum and product of two rational numbers are negative, then the two rational numbers (d)

A is a positive number; B are all negative numbers;

C a positive number and a negative number, the absolute value of the positive number is large;

D a positive number and a negative number, and the absolute value of the negative number is large.

7. If │a│a =-1, then A is (a).

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

8, the following algebraic expression must represent a positive number is (c)

a-2a B a+ 100 C a2+0.0 1D│a+ 1│

9. a+b is reciprocal, and M and N are reciprocal, so there must be (A).

a(m+n)ab = 1 B(m+n)ab = 0 C(a+B)Mn = 1D(a+B)Mn = 0

10, and the value of formula (-2) 13+(-2) 12 is (a).

A -2 B (-2)25 C -225 D -2 12

1 1, the following numbers are known:-16, 6, 0.74, -4), 0, π, where the positive number has (d).

A 1 B 2 C 3 D 4

12, a point starts from the origin for 3 unit lengths on the number axis, moves to the right for 4 unit lengths, and then moves to.

Move to the left by 1 unit length, and the number it represents is (d).

A 6 B 0 C -6 D 0 or 6

Second, fill in patiently (3 points for each question, *** 18 points)

13, │x+2│+(y-3)2=0, then xy =-6.

14, the reciprocal is 0, the absolute value is nonnegative, and the reciprocal is-1' 1.

15. The number represented by the point whose distance from the point representing -3 on the number axis is equal to 2 is -6'- 1.

16, and the largest integer not exceeding (-53 )2 is 2.

The reciprocal of 17 and 3a is the reciprocal of 2a-93, so the value of a is 3.

18, fill in the appropriate numbers according to the law: 18, 14, 34, 3, 15.

Three, careful calculation (6 points per question, ***48 points)

19、0-23÷(-4)3 - 18 20、30×( 12 - 13 )

2 1、-0.252÷(- 12 )3+( 18 - 12 )×(- 1) 100

22、36×( 12 - 13 )2 23、(-4)2×(- 12 )3÷(-3)

24、-42×〔( 1-4)÷6〕3 25、(-2)4+5 12 ×(- 16 )-0.25

26、(-0. 125)×(-35 )×(-8)×53 ×(-5)

Fourth, think about it and do it seriously (6 points for each question, *** 18 points)

27. A highway maintenance team patrolled the north-south highway by bus for emergency repair. One morning, they set out from place A and finally arrived at place B in the evening, and agreed that the north was the positive direction. The record of the day's exercise is as follows (unit: km).

+ 18,-9,+7,- 14,-6,+ 13,-6,-8

Ask where B is in A and how many kilometers apart. If the car consumes 0.2 liters per kilometer, how many liters will it consume that day?

28, a barrel of 40 kg of cooking oil, use up half of the oil in the barrel at a time, so how much cooking oil is left in the barrel for the fourth time?

2.5 liters

29. When the flood season comes, the reservoir has strengthened water level observation. The water level of the previous day was only 0.8m lower than the warning water level. If the plus sign indicates that the water level is higher than the previous day, the minus sign indicates that the water level is lower than the previous day. The five-day observation records are as follows: (unit: meter)

1 2 3 4 5

+0. 18 +0.2 -0. 10 +0. 1 +0. 12

(1) If the warning water level is false, it is marked as "+"above the warning water level and "-"below the warning water level, then how to record the water level in these five days?

1 2 3 4 5

+0. 18 +0.2 -0. 10 +0. 1 +0. 12

(2) As can be seen from the table, how many meters is the water level on the fifth day from the warning water level? Reach or fall below the warning water level? Last/better/previous/last name