What is a tree line?

Small animals have a $......P.......$ surface area relative to their volume, so they lose body heat $.....Q.....$ when it is cold outside.

Rainfall occurs in chaparral during

Consider the following four statements $(a-d)$ regarding certain desert animals like the kangaroo rat:
$(a)$ They have a dark color and high rate of reproduction and excrete solid urine.
$(b)$ They do not drink water,breathe at a slow rate to conserve water,and their body is covered with thick hair.
$(c)$ They feed on dry seeds and do not require drinking water.
$(d)$ They excrete very concentrated urine and do not use water to regulate body temperature.
Which two of the above statements are true?

Which organism does not drink water but uses water produced as a byproduct of its internal metabolic processes?

$A$ kind of similarity found in polar regions and high altitudes is