Since the air is a great thermal isolator, the windows prevent heat exchange better than one made out of a single thick sheet of glass. The air between the thin blankets is not moving around and will form an isolating layer that acts exactly like another blanket, thus improving the thermal isolation
The answer is descent with modification.
Descent with modification practically means that a species have changed appearance wise over long periods of time to adapt to their environments better.
When assessing the heart rate of a 6-month-old infant, you should palpate the brachial or femoral pulse
a variable whose values are independent of changes in the values of other variables