| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.09 |
| Score | 0% | 62% |
In the metric system, what prefix represents 10-3?
mega |
|
kilo |
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milli |
|
centi |
In the metric system, milli is the prefix for 10-3.
In the heart, blood flows from the __________ ventricle to the lungs then back to the heart via the __________ atrium.
right, left |
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left, left |
|
right, right |
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left, right |
The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.
Regulation of heart rhythm occurs in:
cerebellum |
|
nerves |
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medulla |
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cerebrum |
Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.
The hottest of Earth's atmospheric layers is which of the following?
stratosphere |
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mesosphere |
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thermosphere |
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troposphere |
Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.
Sound travels fastest through which of the following media?
metal |
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air |
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vacuum |
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water |
The speed of a sound wave will vary with the medium. Sound travels fastest through media that has particles that are very close together, like metal. Thus, it travels faster through water than through air and doesn't travel at all through a vacuum (there are no particles in empty space to vibrate).