Who has the science final exam for the eighth grade?

Zhejiang education printing plate eighth grade science final examination paper a

Possible relative atomic weight: h-1i-127k-39o-16s-32.

First, multiple-choice questions: (2 points and 60 points for each small question)

1, the following is the light source (c)

A, the moon b, the gem c, the candle flame d, and the movie curtain when watching a movie.

2. The group with different fertilization methods among the following animals is (a)

A, goldfish and whales B, snakes and turtles C, pigeons and cats D, giant salamander and crucian carp.

When a disaster happens, a good way for people trapped in the ruins of buildings to ask for help from the outside world is to knock on the iron pipe. This way is to use iron pipe energy (A).

A, sound transmission b, heat transfer c, loudness d, ventilation

4, in order to make a beam of light parallel, the students in the class put forward the following methods, you think the feasible method is (b).

A, choose a concave lens and put a small light bulb on the focus of the concave lens.

B, choose a convex lens and put a small light bulb on the focus of the convex lens.

C, select a concave lens, and put a small light bulb at twice the focal length of the concave lens.

D. Select a convex lens and place a small light bulb at twice the focal length of the convex lens.

5, a classmate when measuring current with an ammeter, found that the pointer to the left without scale deflection, the reason for this phenomenon is (c).

A, ammeter range is wrong. B, the current in the circuit is too small.

C. the positive and negative poles of the ammeter are connected backwards. The ammeter is short-circuited

6, the following phenomenon, belongs to the unconditional inversion is (D)

A, the sea lion heard the breeder's footsteps and drooled. B, the students heard the bell and ran into the classroom.

C, the driver saw the red light, stop moving. Sand blew into his eyes and tears came out.

7, the following phenomenon belongs to the reflection of light is (C)

A, the phenomenon of solar eclipse B, the circular spot formed by sunlight in the shade of dense trees.

C, the reflection of the mountains on the calm lake D, the small fish playing in the clear lake on the shore

8, in order to explore what is the condition of sound, someone put forward the following experimental scheme, what do you think can explain the experimental problem is (b).

The alarm clock in the bell jar rang. After the air in the bell jar is pumped away, the singing sound is obviously reduced.

B. When the guitar strings make sound, the small pieces of paper placed on the strings will be bounced off by the strings.

C after playing the trumpet, press different keys to make it make different sounds.

D seal the sounding radio in a plastic bag and put it in the water so that people can still hear the sound from the radio.

9. As shown in the figure, the current of lamp L 1 can be measured correctly (C).

10, the following statement about knocking at the door is incorrect (D)

A, the greater the amplitude of drum vibration, the greater the loudness of sound.

B the faster the drum vibrates, the higher the sound frequency.

The loudness of the drum varies with the strength of the drum.

D, the greater the strength of the drum, the better the timbre of the drum.

1 1. In the four scenes shown in the figure, (a) is formed due to the straight-line propagation of light.

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A B C D

12 Dolly the cloned sheep looks like (a)

A ewe b with nuclear donor, ewe c with seedless eggs, surrogate ewe d and part of ABC.

13. In the circuit shown in the figure, A and B are two meters. After closing the switch S, both bulbs can emit light, so the following statement is correct (A)

A, A is ammeter and B is voltmeter.

B, A is voltmeter and B is ammeter.

C, A and B are ammeters, and D, A and B are voltmeters.

14, Fan Zhongyan, a writer in the Song Dynasty, wrote in the immortal masterpiece "The Story of Yueyang Tower": "The moon is thousands of miles away, and the still shadows are heavy", in chapter (c)

A, "Hao Yue" is an artificial light source B, and "Hao Yue" is a natural light source.

C. The "still shadow sink" is the virtual image D formed by reflection, and the "still shadow sink" is the virtual image formed by refraction.

15, as shown in the circuit, when the switch s is closed, it is found that the voltmeter reads zero, and the following guess must be wrong (b).

First, the light L 1 open circuit

B, lamp L2 short circuit

C, lamp L2 open circuit D, voltmeter internal open circuit

16, we hear the sound of objects, because (b)

A, there is a vocal body; B, the sound generator vibrates in the air.

C. The sound generator vibrates in vacuum D. People see the vibration of the sound generator.

17, a 20-year-old boy, a freshman, with average grades, but less than 140 cm in height. He may have (a)

A, dwarfism B, dementia C, diabetes D, hyperthyroidism

18, the distance from the sun to the earth 1, 5×101m, and the time required for the light emitted by the sun to reach the earth is (d).

A, 50 hours b, 500 minutes c, 5× 105 seconds d, 500 seconds

19, Haidian, Beijing) In the four scenes shown in Figure 3, (d) belongs to the refraction of light.

20. The angle between the incident light and the mirror is 55 degrees. If the incident angle is increased by 5 by rotating the plane mirror, the included angle between the incident light and the reflected light will increase to (c).

70 pounds, 75 degrees Celsius, 80 days, 60

2 1. Your neighbor's decoration is noisy, which interferes with your study and life. Which of the following measures is ineffective (a)

A, quickly close the doors and windows. B, plug your ears with cotton.

C, open the window to speed up the air circulation D, hang the quilt on the window.

22. Xiao Ming sees the digital image of the electronic clock opposite the mirror from the flat mirror as shown in the figure, and the time should be (C).

a、2 1∶ 10 B、 10∶2 1

c、 10∶5 1D、 12∶0 1

23, the following narrative, does not belong to the characteristics of adolescent development is (D)

A, the rapid growth of height and weight B, the formation of bisexual reproductive organs

C, the emergence of secondary sexual characteristics D, increased brain excitability

24. In the "convex lens imaging" experiment, when the distance from the candle flame to the lens is 20cm, a reduced image is observed on the screen on the other side of the lens. If the candle flame is 0/5 cm away from the lens/kloc-,then the candle flame passes through the lens (d) on the screen.

A, it must become a reduced real image B, and it must become an equal real image.

C may become an enlarged real image D or a virtual image.

25, can explain the phenomenon that liquid can spread sound is (D)

People on the shore heard the sound of the river flowing.

B, soldiers sleeping on the ground with cattle rocket launchers can hear the sound of horseshoes attacking the enemy at night.

We can hear the sound of the waves beating against the rocks.

D. divers can hear the sound on the shore.

26, the following substances can't be magnetized is (a)

A, carbon b, cobalt c, steel d, nickel

27, as shown in figure 3, which picture describes the magnetic field inductance line is correct (C)?

A, Figure A, Figure B and Figure B

C，C，D，D。

28. Put a horizontal seedling on a spaceship flying in space. After several days of cultivation, the growth direction of roots and stems is

(4)

A, the roots grow downward and the stems grow upward; B, the roots and stems all grow downward.

C, the roots grow laterally, the stems grow upward, and the rhizomes grow laterally.

29, "a millet in spring, 10 thousand seeds in autumn", towering trees are also developed from a seed, in fact, because the seed contains (D) that develops into a complete plant.

A, nutrient b, moisture c, inorganic salt d and embryo

30, skin plays an important role in keeping people's body temperature constant, it is very hot every day in summer (D)

A, most blood vessels contract and sweat secretion decreases; B, most of the blood vessels are relaxed and sweat secretion is reduced.

C, most blood vessels contract, sweat secretion increases D, most blood vessels relax, sweat secretion increases.

Second, fill in the blanks. (Per grid 1 minute, ***40 points)

1， The magnetic induction intensity of each part of the magnet is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

2. A complete circuit consists of four parts: power supply, power consumption, control circuit on-off and power supply flow path.

3. When the sun shines on the blackboard from the window, the words on the blackboard in the classroom are dazzling to the students on one side of the classroom because it happened; Students near the window can clearly see the chalk on the blackboard, which is due to the reason.

Xiao Wang saw Xiao Li's face through the flat mirror, so Xiao Li saw Xiao Wang's face through the flat mirror (choose "can" or "can't"), because of the truth.

5. As shown in figure 1, pull a line parallel to the magnetic needle above the static magnetic needle for guidance.

When the wire is energized, the magnetic needle immediately appears _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

Experiments show that _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. This phenomenon is caused by Danish physics.

The scientist _ _ _ _ _ _ _ first discovered it. He was the first scientist to discover the connection between _ _ _ _ _ _ _.

6. The sound is emitted by _ _ _ _ of the vocal body. The "sharp" voice of female students means that the voice of female students is _ _ _ _ high, because the vocal cord vibration of female students is _ _ _ _ _.

7. The focal length of the camera lens remains unchanged. After taking a bust of Kobayashi with it, Kobayashi wants to take another full-length portrait in the same place. Then the distance between the photographer and Kobayashi should be (fill in "bigger", "smaller" or "unchanged"), and the length of the black box (that is, the distance from the negative to the lens) should be, so as to take clear photos.

8. Among the following objects, there are conductors and insulators. (Write serial number only) ① Earth ② Air ③ Metal ④ Rubber ⑧ Petroleum ⑧ Glass ⑨ Human body ⑨ Carbon rod ⑨ Acid solution ⑨ Salt solution.

9. As shown in the figure, when only S 1 and S2 are closed, the lamp L2 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

To make two lamps in parallel, the correct way is _ _ _ _ _ _ _ _ _ _ _ _,

At this point, the ammeter measures the _ _ _ _ _ _ _ current.

10 As shown in the figure, two plane mirrors MP and PN intersect at an included angle of 60, and a beam of light.

AO is obliquely incident on MP, and after being reflected by two plane mirrors, it coincides with the incident ray AO, but it is square.

On the other hand, the angle between AO and MP is _ _ _ _ _ _ _ _ degrees.

1 1, as shown in the figure, are the structural diagrams of broad bean (left) and corn (right) seeds respectively. According to the picture, the answer is:

(1) is the structure for storing nutrients in broad bean seeds; The structure of storing nutrients in maize seeds is. (Fill in serial number)

(2) The first structure developed in the seeds of Vicia faba and maize is the sum in the graph. (Fill in serial number)

(3) The most important difference between broad beans and corn seeds is.

12. This is the growth and development process diagram of butterflies (as shown in the figure).

(1) Complete this graph.

(2) The growth and development process of butterflies is called _ _ _ _ _ development.

13, (3 points) In order to study the conditions needed for seed germination,

A classmate designed the following three experiments (A, B, C).

Put them in the sun. Please answer the following questions:

(1) Which two devices should be compared to prove that seeds need water for germination?

(2) The purpose of adding oil film on the water surface in the equipment C is

______ __

(3) As far as you know, the germination of seeds is not only full of water,

The required condition is _ _ _ _ _ _ _.

Iii. Drawing questions (2 points for each question, 10)

1. According to the law of light reflection, draw the incident light A0 reflected by the plane mirror in the figure.

2. As shown in the figure, S is the luminous point, S' is the image of S in the plane mirror, L is the light incident on the plane mirror, the position of the plane mirror in the figure and the reflected light of L..

As shown in the figure, there are two dry batteries, two small bulbs, a switch and several wires, an ammeter and a voltmeter. It is required that two dry batteries are connected in series, two bulbs are connected in series, and the switch is closed. The voltmeter can measure the voltage across L 1, and the ammeter can measure the current in the circuit. Please connect the physical object to the circuit as required (the current in the circuit is about 0 and 4A).

4. Change a wire in the figure below and let the ammeter measure the current through L 1;

5. Complete the light path diagram.

IV. Calculation questions (5 points for each question, 10)

1, a resistor R 10 ohm with a resistance value of/kloc-0 is connected in series with another resistor R2, and then connected to the circuit. It is known that the power supply voltage is 12 volts, and the voltage across R2 is 9 volts. Find: (1) the current intensity through R 1; (2)R2' s resistance.

2. In the circuit shown in the figure, the power supply voltage is 6 volts, the resistance of R2 is 10 ohm, and the current intensity through R 1 is 0 and 4 amps. Find the current intensity through resistor R2 (1). (2) The current strength of the main road. (3) The total resistance of the circuit.

Zhejiang education printing plate eighth grade science final examination paper a

I. Multiple-choice questions: (2 points for each question, ***60 points)

CAABC DCBCD AAACB BADDC CBBCD ACDDD

Second, fill in the blanks. (Per grid 1 minute, ***40 points)

1, different; Both ends; Middle; The strongest part of the magnet 2. Power supply,; Electrical appliances; , switch; Conductor

3. Specular reflection; Diffuse reflection 4 can also be used; The light path is reversible.

5, deflection, return to the original position, there is a magnetic field around the electrified wire, Oster, electricity and magnetism.

6, vibration, tone (or frequency), fast 7. Bigger; Smaller 7. ① ③ ⑥ ⑨ ⑩,; ②④⑤⑥

8. If the light L 1 is not on, only S2 is closed and only S 1 is disconnected in parallel.

9, 30 degrees 10, (1)E J (2) B I (3) two broad bean seed cotyledons and one corn seed leaf.

1 1, (1) The pupa (2) is completely abnormal.

12, (1)A and B(2) are isolated from the air, and the seeds in C can't get oxygen. (3) Suitable temperature and sufficient oxygen.

Iii. Drawing questions (10).

Four, the calculation problem (10)

1, (1) 0,3a (2) 30 euros

2. (1) 0,6a (2)1a (3) 6 euros

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