churn in Business English. churnnoun [ U ] Preventing customer churn is a major concern for mobile service providers, since 20-40% of customers leave their providers in a given year. Employee churn for new hires increased by 33% for the third straight year.
For 18 months, the baby nurses while its mother is on land, or it swims underwater to suckle. When it dives, the calf closes its nose and ears to block out water. All hippos have this ability. They also have membranes that cover and protect their eyes while they are underwater.
Although they live in the water, marine mammals like whales, dolphins, seals and sea lions, as well as reptiles like sea turtles, need to breathe air. So while they spend their life swimming in the ocean, they must still come to the surface of the water from time to time to take a breath of air. Fish breathe air through their gills. Marine mammals have lungs and take in oxygen through their blow holes or, in the case of manatees and dugongs, through their snouts. Unlike humans, these marine mammals breathe voluntarily. Animals need oxygen to survive. Animals like mammals, birds and reptiles get their oxygen by breathing air, while animals like fish absorb the oxygen they need from water taken in through their gills, Koontz said. Nine minutes is about the very longest time a human can hold their breath under water.