This depends... I live in Southern Michigan, which is deciduous forest because they cover most of the Northern US.
B white blood cells function as your immune systems body guards. Osmosis Jones is a great movie to watch in order to learn more about it :)
Answer -
T-Cell - White blood cell = Fight off Intruders in the body
B-Cell - Macrophages = Creates Antibodies against antigen.
Cell Differentiate - Stem Cells = My favorite cell of all time in animal because they can turn into almost any cell like neural, signaling, euthyroid. Etc
The rotation of the Earth in its axis