| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
Which of the following describes the Earth's outer core?
liquid |
|
solid |
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primarily solid |
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makes up most of the Earth's volume |
The Earth's core is divided into the liquid outer core (1,430 miles or 2,300 km radius) and the solid inner core (745 miles or 1,200 km radius).
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
reflection |
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sound radiation |
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Doppler effect |
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refraction |
The Doppler effect occurs when the source or listener (or both) of sound waves is moving. If they're moving closer together, the listener perceives the sound with a higher pitch and, when they're moving apart, the listener perceives the sound with a lower pitch.
The first step in the water cycle is:
precipitation |
|
evaporation |
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reclamation |
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infiltration |
The water (hydrologic) cycle describes the movement of water from Earth through the atmosphere and back to Earth. The cycle starts when water evaporates into a gas from bodies of water like rivers, lakes and oceans or transpirates from the leaves of plants.
The __________ nervous system controls voluntary actions.
central |
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peripheral |
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autonomic |
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somatic |
Part of the peripheral nervous system, the somatic nervous system is made up of nerve fibers that send sensory information to the central nervous system and control voluntary actions.
Which of these digestive enzymes is not produced by the pancreas?
gastric acid |
|
pancreatic amylase |
|
lipase |
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trypsin |
The acids produced by the pancreas contain several enzymes that aid in digestion. Lipase converts fat to glycerol and fatty acids. Pancreatic amylase breaks down complex carbohydrates into simple sugars. Trypsin converts polypeptides (the building blocks of protein) into amino acids.