Penguins are flightless birds.They cannot fly,but they are verygood at swimming. When they swim,their wings push them at a speed up to 25 miles per hour. They can swim faster than a human. They live only in the southern hemisphere. The emperor penguin is 4 feet high when it stands up and weighs about 40 pound or 18 kilograms.
(1 pound = 0.454 kilograms)