This would be D) The atmosphere :P
Climate , temperature , and other organisms
<span>structures that monitor co2 and o2 concentration in the blood called chemoreceptor because it detects chemical inside blood, in this case, CO2 or O2. Those chemoreceptors found in aortic body or carotid vessel. Bifurcated vessel probably is carotid vessel. </span>
A method of procedure that has characterized natural science since the 17th century of systematic,consisting in systematic observation,measurment,experiment,formulation
