According to the passage, which of the following can be found in the greatest number of different climate areas on Earth

A．they have developed advanced forms of transportation
B．they have learned how to process seawater for drinking
C．their body temperature can vary considerably
D．their shelters and clothing help them to adapt to the environment

A．to avoid being eaten by arctic animals
B．because fertilizer is not readily available
C．to minimize exposure to the cold
D．because unfrozen water plants are very scarce