The first grade exam 1.
Only one of the four options in each of the following multiple-choice questions (4 points for each question, 40 points for * * *) is correct. Please write down the English letters before the correct answers in the table below.
1. If the reciprocal of the negative reciprocal of A is 8 and the reciprocal of the reciprocal of B is 8, then ()
A, a=b B, a < BC, BC. b D、ab= 1
2. If two right triangles are placed as shown in figure 1, the ratio of degrees of ∠BFE to ∠CAF is equal to ().
a、8 B、9 C、 10 D、 1 1
3. There are four judgments about rational numbers A and B:
① If |a|=b, then a = b；; ② If |a| >b, then |a| >| b |
③ If a=-b, then; ④ If | a | < |b|, then a
The number of correct judgments is ()
a、 1 B、2 C、3 D、4
4. If the ratio of degrees of external angles of ∠A, ∠B and ∠C in triangle ABC is 5:4:3, then the ratio of degrees of ∠A, ∠B and ∠C is ().
a、5:4:3 B、3:4:5 C、 1:2:3 D3:2: 1
5, 6 people completed a project in 35 days, if you add 8 people with the same work efficiency, then the number of days before and after the completion of this project is ().
A, B, C, D, 65 years old
6. If the lengths of the three sides of a triangle are A, B and C respectively, and the identities are satisfied, then the triangle is ().
A, acute triangle b, right triangle c, obtuse triangle d, equilateral triangle
7，when，established，then =()
a、0 B、 1 C、99.25 D、99.75
8. As shown in Figure 2, a square pool is just surrounded by four regular N polygons.
If the floor tile is covered, then n is equal to ()
A, 4 B, 6 C, 8 D, 10 Figure 2
9. If, then ()
A, B, C, D,
10, Party A and Party B ride from A to B along the same route (uniform speed). It takes 30 minutes for Party A and 40 minutes for Party B. If Party B leaves 6 minutes earlier than Party A, it will take () minutes for Party B to arrive at B;
a、25 B、20 C、 16 D、 10
Two. Group A fills in the blanks (4 points for each small question, ***40 points)
1 1, calculation: =;
12, if a=2009 and b= -20 10, then;
13, if A and B are reciprocal, C and D are reciprocal, and the absolute value of X is equal to 2, the value is;
14. If the new two-digit number obtained by exchanging the ten digits of a two-digit number with a one-digit number is three times the sum of its numbers, the original two-digit number is;
15. There are several identical balls in the box. After A takes half, B takes the rest, and C takes five more. There are three balls left, so there are three balls in the box.
16, if, where a, b and c represent non-zero numbers, then;
17, as shown in figure 3, ∠ C = 45, ∠ B = 45+2α, as shown in figure 3.
∠ ∠BAD = 45+3α, AE divides∠∠ Bad equally, then∠∠ ∠CAE =；;
18, a prime number with two digits, the absolute value of the difference between one digit and ten digits is equal to 5,
Such two prime numbers are;
19. If A and B are reciprocal, then;
20. as shown in figure 4, in △ABC, e is the intersection of AD and CF, AE=ED,
It is known that the area of △ABC is1the area of △ BEF is,
Delta △AEF area is _ _ _ _ _ _ _ _; Figure 4
Three. Group B fills in the blanks (8 points for each small question, ***40 points)
2 1, here are six inferences:
① Because both sides of a right angle are on a straight line, this straight line is a right angle;
(2) Because both sides of the fillet are on a ray, the ray is a fillet;
(3) because the sector is a part of a circle, a part of the circumference is a sector;
(4) Because parallel line segments have no intersection, two disjoint line segments are parallel;
⑤ Because all sides of a square are equal, a quadrilateral with equal sides is a square;
⑥ Because an isosceles triangle has two equal internal angles, two triangles with equal internal angles are isosceles triangles;
Among them, two conclusions are correct, and their serial numbers are;
22. Teacher Chen bought souvenirs for each of the 42 students, including: each pen of 12 yuan, each compass of 4 yuan, and a dictionary of 16 yuan, which cost 2 16 yuan, so Teacher Chen bought a pen and a dictionary book.
23. As shown in Figure 5, in the parallelogram ABCD, the bisector of ∠BAD intersects the BC side at point M,
And MD shares ∠AMC, if ∠ MDC = 45, ∠ bad = 0,
∠ABC =； Figure 5
24. It is stipulated that if m is the smallest prime number and n is the smallest composite number greater than 100, then _ _ _ _ _ _ _ _ _ _ _ _;
25. If yes, then _ _ _ _ _ _ _ _.