Troposphere
The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.
Stratosphere
The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high. The ozone layer, which absorbs and scatters the solar ultraviolet radiation, is in this layer.
Mesosphere
The mesosphere starts just above the stratosphere and extends to 85 kilometers (53 miles) high. Meteors burn up in this layer
Thermosphere
The thermosphere starts just above the mesosphere and extends to 600 kilometers (372 miles) high. Aurora and satellites occur in this layer.
Ionosphere
The ionosphere is an abundant layer of electrons and ionized atoms and molecules that stretches from about 48 kilometers (30 miles) above the surface to the edge of space at about 965 km (600 mi), overlapping into the mesosphere and thermosphere. This dynamic region grows and shrinks based on solar conditions and divides further into the sub-regions: D, E and F; based on what wavelength of solar radiation is absorbed. The ionosphere is a critical link in the chain of Sun-Earth interactions. This region is what makes radio communications possible.
Exosphere
This is the upper limit of our atmosphere. It extends from the top of the thermosphere up to 10,000 km (6,200 mi).
B. Two protons and two neutrons
Answer:
My pretest behaviors were triggered by the sympathetic nervous system, while my body returned to its normal state by the way of the parasympathetic nervous system, after the test.
Explanation:
The sympathetic nervous system and the parasympathetic nervous system are part of the autonomic nervous system. The main function of the autonomic nervous system is to regulate the heart, kidneys, and liver which are not under voluntary control. The regulation of the body’s unconscious actions is executed through the sympathetic and the parasympathetic nervous system.
Upon exposure to stressors or threats, the sympathetic nervous system is triggered. Epinephrine and norepinephrine are then released, causing acceleration of the heart, constriction of blood vessels, increase in blood pressure, profuse sweating and other related responses against stress. The sympathetic nervous system controls all these involuntary responses that could be termed “fight-flight-or-freeze” response.
On the other hand, the parasympathetic nervous system initiates what is termed “rest and digest” response, which occurs immediately after the “fight-flight-or-freeze” phase response to stress is over. The body is returned to its normal state by the parasympathetic nervous system. The parasympathetic nervous system releases acetylcholine, which regulates the function of the body during a period of rest or recuperation.
Answer:
D the train
Explanation:
The train is safe very fast and was the first built
HI there!!!!!!
It would probably be the heart, brain or our muscles; they are constantly working !