| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.08 |
| Score | 0% | 62% |
During the water cycle, water enters the atmosphere as a gas through which process?
both evaporation and transpiration |
|
transpiration |
|
evaporation |
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precipitation |
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.
A human heart consists of how many chambers?
1 |
|
4 |
|
2 |
|
8 |
The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.
What prevents blood pumped out of the ventricles from flowing back into the heart?
capillaries |
|
platelets |
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atria |
|
valves |
The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.
Cirrus clouds are thin, wispy clouds composed of ice crystals. At what elevation to cirrus clouds form?
ground level |
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mid-altitude |
|
low-altitude |
|
high-altitude |
Cirrus clouds are thin, wispy high-altitude clouds composed of ice crystals that originate from the freezing of supercooled water droplets. Cirrus clouds generally occur in fair weather and point in the direction of air movement at their elevation.
Earth's history is divided into time periods, which of these is the shortest time period?
eon |
|
period |
|
epoch |
|
age |
The Earth is approximately 4.6 billion years old and its history is divided into time periods based on the events that took place and the forms of life that were dominant during those periods. The largest graduation of time is the eon and each eon is subdivided into eras, eras into periods, periods into epochs, and epochs into ages.