Create your own cartoon of a negative feedback system of the respiratory system

Negative Feed Back system - " Some times an organ stops or interrupts a process or function in order to stabilize its self and the body, mainly the output or product of the process is lessened in order to control the situation such mechanism is known as negative feed back system."

Explanation:

Negative feedback system in Lungs

Now in lungs, the respiratory system  maintains the normal partial pressure of the arterial oxygen and Carbon dioxide. As the partial pressure if exerted by them has a very high influence on the blood pH  and can cause imbalance in the blood pH. So for this reason the negative feed back system is present.

As the body sends the message to the controlling hub of human body and then it starts the process of stabilizing the whole system back to normal by rearrangements of components or parts, along with secretion of some chemicals in  the human body.

Moreover a sketch is drawn which shows the  feedback mechanism in a more simple way.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.