Well, a typical "he" will be male. In human, this means that "he" will produce hormone testosterone and not estrogen which is what "she" will produce. Also, "he" will not have a mammary glands...
Cryogenics is the study of the production of very low temperatures (below –150 °C, –238 °F or 123 K) and the behavior of materials at those temperatures. (Rather than the familiar temperature...