The answer is: An air conditioner that turns on if the temperature gets too hot.
Even though they hurt you emotionally, Negative feedbacks serve their own important function. They keep your feet on the ground and prevent you from getting too arrogant.
This function is similar as a cooling air conditioner. Hot temperature in the comparison above represent your arrogance and the air conditioner represent the negative feedback.
If the inner lining of the air sacs neither thin nor highly vascularized, then it can be inferred that AIR SACS ARE CANNOT BE THE SITES OF GASEOUS EXCHANGE BETWEEN AIR AND BLOOD. Air sacs are generally lined with mucus and surrounded with blood capillaries.
In case of birds, air sacs play an important role in respiratory system.
Carbon dioxide because every other option requires an input.
It's either A. or C. because since its near the equator it's not going to be dry.
