It means , one , only , single .. hopes this helps
There are two types of polar climate: ET, or tundra climate; and EF, or ice cap climate. A tundra climate is characterized by having at least one month whose average temperature is above 0 °C (32 °F), while an ice cap climate has no months above 0 °C (32 °F).
tectonic plates in the earth's crust has moved almost every piece of land from its original spot. On average, tectonic plates moved land masses about 2.3 CM a year.
When a Stickleback fish feels threatened, it will flare out its pair of pelvic spines and three dorsal spines, making it difficult for predators to swallow them.
