Answer:D
Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.
Well, no.
Chicken pox are contagious, and acne is not. Also you would be very sick if you had chicken pox.
In appearance, I wouldn't go as far and say that they are alike, or similar as Chicken pox spread across the whole body.
Hope this helps!
mean is all values added together and divided by number if values. mode is most often. median is middle cross from both sides
Olivine, pyroxene, amphibole, mica, and quartz
