(Examination time: 100 minutes; 100)
Choose one carefully first (3 points for each small question, 30 points for * * *).
1, in the following groups, the one that is not the same item is ()
A, 4xy3 and 5y3x B, 6 and c, -9m2n and 9m2n D, 2abc and 2bcd.
2, the following statement is correct ()
A, equiangular means that vertex B and congruent angle are equal.
C, two straight lines are parallel, and the internal angles on the same side are equal; D, the complementary angle of the same angle is equal.
3. As shown in the figure, from ∠ 1=∠2, () can be obtained.
BC, BC, BC.
C, AD‖BC and AB‖CD D, ∠3=∠4.
4. The approximate value of 0.030570 obtained by rounding method is ()
a，3 B，4 C，5 D，6
5. The winning rate of a game is 1%, and Xiaohua bought a lottery ticket of 100. The following statement is correct ().
I will definitely win the prize. B, I'm sure I won't win the prize, as shown in the picture.
C, the chances of winning the prize are high, and D is unlikely to win the prize.
6, the following formula can be calculated by the square difference formula is ()
a 、( 3a+B )( 3 B-a)B(x+ 1 )(-x- 1)C 、( 2x-y)(-2x+y) D 、(-m+n)(-m-n)
7. If x 2+ax+9 = (x+3) 2, the value of a is ().
a、3 B、3 C、6 D、6
8. The probability of a bird foraging freely on the floor tile and finally stopping on the white square brick is ()
A, B, C, D,
9. If AM = 3 and AN = 5, the value of a3m-2n is ().
a 、- 1 B、2 C、D 、-675
10, as shown in the figure, fold the rectangular ABCD in half along EF, if ∠ 1 = 500,
Then ∠AEF equals.
A 500 B 800 C 650 D 1 150
Two, fill in one and fill in one (2 points for each space, ***25 points)
1 1 is a term, and the degree and coefficient of the highest term are respectively.
1 2, ∠ 1 and ∠2 are complementary, ∠2 and ∠3 are complementary, ∠ 1 = 63, then ∠3=
13, Xiaogang's height is about 154cm, which is accurate. Keep this number to two significant figures: m.
14. According to some data, the forest called "the lung of the earth" is disappearing from the earth at the rate of15,000,000 hectares per year, and the annual forest loss is expressed as _ _ _ _ _ _ _ _ hectares by scientific notation.
15. The probability of finding a red ball from an opaque box is. It is known that the number of red balls in the box is six
There are balls in the box.
16 and figure (1), when the cut ∠AOB increases 15, ∠COD increases.
17. When the straw sucks the beverage in the can, as shown in Figure (2), ∠1=10, ∠2= (the top and bottom of the can are parallel to each other).
Figure (1) Figure (2) Figure (3)
18. There is a spotlight at the top of the parallel building. When the beams intersect, as shown in Figure (3), ∠ 1+∠ 2+∠ 3 = _ _
19 Fill in the blanks in reading: (65438+ 0 point for each blank in this question) △ What is the sum of △ABC, ∠A, ∠B and ∠C? Why?
Solution: ∠A+∠B+∠C=
Reason: make ∠ACD=∠A and extend BC to E.
∠ 1=∠A (manufactured)
∴AB‖CD()
∴∠B=()
And ∠ACB+∠ 1+∠2=
∴∠ACB++= (equivalent substitution)
Solution (***45 points)
20. Calculation questions (3 points for each question, *** 15 points)
9(x+2)(x-2)-(3x-2)2
(2x-y+ 1)(2x+y- 1)
(Calculated by multiplication formula)
2 1.(4 points) Simplified evaluation: [(2A+B) 2-(B-A) (A+B)] ÷ 2A at this time, A = 2, B =-
22(4 points) It is known that ∠AOB, point P is on OA, please take P as vertex and PA as one side for ∠ APC = ∠ O.
(Don't write, but be sure to keep the trace of painting)
Q: Are PC and OB necessarily parallel?
A:
23(4 points) As shown in the figure, ∠ 1 = 120 and ∠ C = 60 are known, which explains the reason of AB‖CD.
24.(5 points) It is known that AB‖CD, BE and CF are equally divided into ∠ABC∠BCD.
Explore the positional relationship between be and CF and explain the reasons.
25.(4 points) The following is the average precipitation of several cities in China in March this year.
Region Kunming Guangzhou Haikou Shanghai
Precipitation (ml) 1 1 33 22 44
Can you make an image statistical chart to show the average precipitation in these areas in March?
26.(4 points) A young lady tore off the labels of 10 boxes of vegetables. Now every box looks the same, but she knows there are three boxes of corn, two boxes of spinach, four boxes of beans and one box of potatoes. She randomly took out a box and opened it. Q:
(1) What is the probability of corn in the box? (2) What is the probability that there are beans in the box?
(3) What is the probability that it is not spinach in the box? (4) What is the probability that there are beans or potatoes in the box?
27.(5 points) What is the relationship between ∠ b, ∠ bed and ∠ d in Figure 2 and Figure 3 given AB//CD? Please use equations to express their relationship and explain the reason for one of them.