Water erosion is usually what people think of, but ice, wind and gravity can also cause erosion.
Water erosion is usually along rivers. As the water moves quickly by it rubs on the rock and dirt, causing rivers to slowly get wider.
Ice erosion is caused by glaciers. Sometimes it's a glacier rubbing against land, and there's a lake that was made by a glacier making it's way onto land and then melting.
Wind erosion is a big problem in fields and large open plains with loose dirt. The wind just blows all the dirt away.
Gravity can cause erosion and cliffs. Sometimes along a mountain or cliff the rock won't be able to hold itself up anymore, and gravity will pull it down.
Your answer would be all of them. Wind, water, ice, and gravity.
Answer: Positive feedback loop
Explanation:
Even before the food reaches the stomach (before ingesting it), the glands of the stomach mucosa begin to release its gastric secretion. The main characteristic of this secretion is acidity, as measured by pH (one of the physiological variables).
This acidity is a result of the presence of hydrochloric acid, which is part of the secretion composition. In addition to it, water, pepsinogen (which will give rise to the enzyme pepsin) and the intrinsic factor. The acid has a function of the protection of the entire system by eliminating microorganisms. It is also responsible for the activation of pepsin (which only occurs with acid pH), the enzyme that digests proteins containing the amino acids leucine or phenylalanine or tryptophan or tyrosine.
The concept of Positive feedback loop states that the body tries to increase the value of a variable (acidity, in the case of pepsinogen) when it is below its optimal value (called a point adjustment) and decreases this value when it is above optimal.
Traditionally the unit was the kilo-calorie but commonly just referred to as calorie. today's SI unit is the Joule...
To warm up easily. In forest there isn't very much sunlight and darker colour allows a lizard to absorb sun warmth more efficiently