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Science, 8th grade
1. Which of the following is an important factor in explaining why seasons occur on Earth?
Earth rotates on its axis.
The Sun rotates on its axis.
Earth's axis is tilted.
The Sun's axis is tilted.

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2. Mary went for a cycle ride during which she had a puncture. She repaired it straight away and immediately continued her ride. The graph shows the progress she made during the ride.

About how long did it take Mary to mend the puncture?

20 minutes
30 minutes
40 minutes
70 minutes

3. In living organisms, the level of organization from least complex to most complex is
cell, tissue, organ, organism
cell, organ, tissue, organism
tissue, cell, organ, organism
tissue, organ, cell, organism

4. The BEST reason for including protein in a healthy diet is because it is the main source of:
energy for the body
fiber for digestion
raw material for cell growth and repair
vitamins for fighting diseases

5. A person in a dark room looking through a window can clearly see a person outside in the daylight. But a person outside cannot see the person inside. Why does this happen?
There is not enough light being reflected off the person in the room.
Light rays cannot pass through a window twice.
Outside light does not pass through windows.
Sunlight is not as intense as other sources of light.

6. Work is done when an object is moved in the direction of an applied force. A person performed different tasks as shown in the diagrams below. In which diagram is the person doing work?

7. Colored alcohol is used in some glass thermometers. When placed in air of different temperatures, the column of alcohol rises or falls in the glass thermometer. Which of the following best explains why the height of the alcohol column changes?
The glass contracts when heated.
The alcohol contracts when heated.
The glass expands more than the alcohol when heated.
The alcohol expands more than the glass when heated.

8. Which of the following organisms are used to convert milk to yogurt?
Bacteria
Protozoa
Viruses
Algae

9. Oxygen, hydrogen, and water are substances. Which of these substances are elements?
oxygen, hydrogen and water
oxygen and hydrogen only
oxygen only
water only

10. Sunscreen is used to protect the skin from exposure to which type of solar radiation?
Visible
X-rays
Infrared
Ultraviolet
Microwaves

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11. The diagram above shows the Earth's path around the Sun and the tilt of Earth's axis. Which of the following patterns on Earth is caused by the tilt of Earth's axis?
seasons
day and night
years
time zones

12. Which food contains the highest percentage of protein?
rice
dates
carrots
chicken

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13. The diagram above shows a mountain. The prevailing wind direction and average air temperature at different elevations on both sides of the mountain are indicated. Which feature is probably located at the base of the mountain at location X?
a dry region
a jungle
a glacier
a large lake
a rain forest

14. What is the main function of chlorophyll in plants?
To absorb light energy
To break down carbon dioxide
To make plants' leaves poisonous to insects
To protect plants from disease

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15. What is organ X?
liver
stomach
small intestine
large intestine

16. What is the main function of red blood cells?
To fight disease in the body
To carry oxygen to all parts of the body
To remove carbon monoxide from all parts of the body
To produce materials which cause the blood to clot

17. Some chemical reactions absorb energy, while others release energy. Of the chemical reactions in burning coal and exploding fireworks, which will release energy?
Burning coal only
Exploding fireworks only
Both burning coal and exploding fireworks
Neither burning coal nor exploding fireworks

18. Which gas could cause rust to form on a metal can?
Hydrogen
Oxygen
Nitrogen
Helium

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19. The diagram shows four identical size rods each of a different material sealed into the bottom of a container. The same amount of wax is placed on the end of each rod and then the container is filled with boiling water. On which rod will the wax melt first?
Glass rod
Wooden rod
Metal rod
Plastic rod

20. Two open bottles, one filled with vinegar and the other with olive oil, were left on a window sill in the Sun. Several days later it was observed that the bottles were no longer full. What can be concluded from this observation?
Vinegar evaporates faster than olive oil.
Olive oil evaporates faster than vinegar.
Both vinegar and olive oil evaporate.
Only liquids containing water evaporate.
Direct sunlight is needed for evaporation.