<span>The correct answer for this question is A - Scientists ask testable questions and devise ways in which they can answer those questions through experimentation or observation. The rest of the possible answers for this question only describe some scientists.</span>
1. The group nearest the end or with the shortest stem of a phylogenetic tree has evolved most recently. In this case it is eutherians.
2. The group with the longest stem has been around the longest: fish
3. A direct common ancestor will share the same immediate line, like marsupials and eutherians. Fish and marsupials do not have a common direct ancestor.
Birds
Birds are organisms which utilize a one-way air flow through their lungs to maximize air flow efficiency and <span>oxygen consumption
</span>The process of respiration is essential in the oxygen/carbon dioxide cycle. Respiration removes OXYGEN <span>from the atmosphere and produces and releases </span>CARBON DIOXIDE to the atmosphere.answer is letter D.
<span>Respiration driven by a mechanical series called inhalation and exhalation. We inhale or breathe in oxygen and exhale or breathe out carbon dioxide. </span>
