The substance is substrate
In this scenario, E.coli is living in our intestines, which means we are providing them with a place to live and nutrients to survive. It is also stated that they help us break down some foods.
so as you can see, we benefit them, and they benefit us.
Based on this, after defining all of your options, you will find your answer.
Answer:
i stongly belive that "Lungs of the Earth" refers to the trees
Explanation: because trees act just like lungs
The correct answer is "<span>a layer of smooth </span><span>muscle".
</span>In an individual's mouth, gut, and the small intestine, the mucosa, which holds tiny glands, which secrete juices in order to assist in digesting food<span>. The </span>digestive<span> tract also holds a layer of smooth </span>muscle, which <span>aids in breaking down </span>food<span> and move it along the digestive tract.</span>
The nervous system helps:
Receptors in muscles provide the brain with information about body position and movement.
The brain controls the contraction of skeletal muscle.
The nervous system regulates the speed at which food moves through the digestive tract.
The nervous system regulates respiratory rate
The nervous system regulates heart rate and blood pressure.
Source: https://faculty.washington.edu/chudler/organ.html