| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.34 |
| Score | 0% | 67% |
Which is the proper order of Earth's atmospheric layers from the surface up to space?
mesosphere, thermosphere, stratosphere, troposphere |
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troposphere, stratosphere, mesosphere, thermosphere |
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stratosphere, troposphere, mesosphere, thermosphere |
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thermosphere, mesosphere, stratosphere, troposphere |
The troposphere is the closest layer to Earth, followed by the stratosphere, mesosphere, and finally the thermosphere which borders space.
Blood pressure is generally highest in which of the following?
veins |
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arteries |
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heart |
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capillaries |
Arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood.
As part of digestion, the liver produces bile which breaks down:
fat |
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sugars |
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protein |
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starches |
The liver produces bile which emulsifies (separates) fat.
The rate of vibration of sound is called:
volume |
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amplitude |
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frequency |
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period |
The rate of vibration of sound is called frequency and is measured in hertz (Hz). One hertz is one repetition per second and sounds with high frequency have a higher pitch than sounds with lower frequency. Humans can hear sounds in the range of 20 Hz to 20 kHz.
Blood is created in:
bone marrow |
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the liver |
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red blood cells |
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the heart |
Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.