Explain why c02 levels in the atmosphere are lower in spring/summer than in fall/winter. show evidence

Among what trees do is take in CO2 and give out O2.

During spring/summer, there are more trees (living) than in fall/winter.

So, there is less CO2 in the atmosphere in spring/summer.

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .