0 is odd or even, nonnegative even sets such as and are represented by enumeration

0 ah, now it's even, because the concept of even number is even = 2n, and N can take 0

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1. A school organized 340 teachers and students to carry out long-distance inspection activities, with 170 Pieces of luggage. It plans to rent 10 cars of two models a and B. It is understood that each car of a can carry up to 40 people and 16 pieces of luggage, and each car of B can carry up to 30 people and 20 pieces of luggage. (1) please help the school to design all feasible car rental schemes; (2) if the rent of car a is 2000 yuan per car, the rent of car B will be reduced It's 1800 yuan per car. What's the best way to save car rental?
2. Three trucks carry 480 cases of apples. How many cases can five trucks carry?
3. A number is both a multiple of 8 and a factor of 72. This number may be (), or ()
4. As shown in the figure, △ ABC is an equilateral triangle, D is a point on BC, and ∠ ade = 60? Intersection ∠ ACB bisector of external angle is at E
5. The angle ABC is an equilateral triangle, CE bisects the angle ACF, D is a point on BC, and the angle ade = 60 ° proves ad = De The angle ACF is the outer angle of an equilateral triangle
6. As shown in the figure, triangle ABC is an equilateral triangle, D is a point on BC, angle ade = 60 degrees, CE bisects the outer angle ACF of triangle ACB, proving: ad = De
7. In the triangle ABC, the angle ACB is equal to 90 degrees, the points E and F are on the edge AB, and the angle CEB = angle ECB, the angle CFA = angle FCA, and the degree of the angle ECF is calculated
8. In △ ABC, ab = AC, D is the point on BC, DF ⊥ AC is on fed ⊥ BC is on D, if ∠ AED = 150 °, calculate the degree of ∠ EDF?
9. As shown in the figure, △ ABC, ad is the angular bisector, e and F are the points on AC and ab respectively, and ∠ AED + ∠ AFD = 180 °. What is the relationship between de and DF, and explain the reason
10. As shown in the figure, in the triangle ABC, ad bisects ∠ BAC, BC intersects D, e and F are the points on AB and AC respectively. If the angle AED + ∠ AFD = 180 °, then de = DF
11. Given that points a and B are on the number axis, and a and B are symmetrical about the origin, if the numbers corresponding to points a and B are X-1 of X and 2-x of X + 1 respectively, try to find two points a and B The distance between them
12. Kobayashi and Kobayashi are both stamp collectors. Kobayashi collected 72 stamps. The ratio of Kobayashi to Kobayashi is 4:3 To know how many stamps Xiao Gang collected, how many ways can you answer them
13. Let an be an arithmetic sequence with nonzero tolerance, Sn be the sum of the first n terms of an, and S3 ^ 2 = 9s2, S4 = 4s2, The formula of finding sequence an
14. 1、 Fill in (15 pieces) 1. The sun is the largest () and () on earth 2. Light is transmitted in the form of (). The speed of light propagation is very fast, about () thousand kilometers per second. The distance between the sun and the earth is about 150 million kilometers, and it takes () minutes for the light from the sun to reach the earth 3. In the food chain, the organisms that can make their own food are called (). The organisms that consume the food made by other organisms directly or indirectly are called (). The food chain usually starts from () and ends at () 4. Seed germination needs (), suitable (), and sufficient () 5. An object like an electric light that can emit light on its own is called () 6. We found that earthworms like to live in (), () environment 2、 Judgment (10) 1. In order to observe the light source, Xiao Ming often looks directly at the light source with his eyes 2. The amount of light has nothing to do with the intensity and temperature 3. Seeds will not germinate in dark environment 4. In order to study whether the seeds germinate fast under the condition of moderate water or little water, the water content of the seeds in the experimental group and the control group are different, and the conditions of temperature, nutrient, air and light are also different 5. In the experiment of mung bean seed germination, the number of seeds in each group should be at least two 6. Solar energy is a kind of clean, safe and energy-saving energy. People are vigorously developing and using solar energy 7. If one kind of living thing is extinct, it will affect the survival of many other living things. Therefore, to protect one kind of living thing is to protect many living things 8. All the light sources are heating when they are emitting light 9. While the sun brings us light, it also brings us warmth 10. The transmission route of sunlight cannot be changed 3、 Multiple choice questions (10) 1. The doctor brought a frontal mirror to examine the patient's ears, which solved the problem by using () A. Direct light B, reflection of light 2. In contrast experiments, we generally control () condition unchanged A one B two C three 3. Apple trees are not suitable to be planted in tropical areas, and oranges are not suitable to be planted in the north A. Sunshine B, temperature C, water D, air 4. Space suits are usually made of silver for () A. Absorb solar energy B. prevent radiation C. beautiful 5. Fish must live in the water. Once they leave the water, they will die. This is because () A. Organisms affect the environment B. organisms change the environment C. organisms depend on the environment 4、 Various mirrors are used in many places of life and production, and the following types of mirrors are connected The doctor's frontal mirror Concave mirror of automobile Periscope plane mirror Convex lens of spherical mirror at road corner Solar cooker 5、 Short answer: 1. Use the animals given below to write three food chains: snake, frog, locust, bird, vole, rice and owl (6) 2. Please design and make a simple solar water heater. (requirements: write down the materials and simple steps or draw a simple diagram) (4 pieces)
15. Function y = 2-2x what is the square unit of the area of the triangle formed by the image and two coordinate axes
16. Conversion of capacitance units? Capacitance units include h, uh, pH, etc. What's the conversion between them? It seems that there is any relationship between MH and NH?
17. What is a ton represented by a symbol
18. AC power problem The maximum value of alternating current (sine cosine type) is 250 root 2 v. if a fuse is connected, the maximum current allowed by the fuse is 10a, and the maximum output power allowed is 5000W. What's wrong? The voltage is 250 bar No. 2, and the fuse is the effective value, so the maximum current is 10 bar No. 2, and the maximum power is 250 bar No. 2 * 10 bar No. 2 = 5000?
19. When the bulb is always marked with "220 V 40 W", the current passing through the filament is - A, one degree of electric energy for the lamp to work normally for - hours There must be a way to solve the problem!
20. As shown in the figure, ab ∥ CD, ∠ ACB = 90 °, e is the midpoint of AB, CE = CD, de and AC intersect at F.; De is perpendicular to AC, and angle ACD = angle As shown in the figure, it is known that AB / / CD, ∠ ACB = 90 °, e is the midpoint of AB, CE = CD, de and AC intersect at F, and the verification is as follows: