【B1】 【B10】

There are 17 kinds of penguins in the world. All of them live in the southern hemisphere. Only a few species live on the continent of Antarctica at the bottom of the world. The emperor penguins are the largest. They are about 100 centimeters tall and weigh about 30 kilograms. Their special method of mating makes them different from all other penguins.
   For thousands of years the emperor penguins have lived on the freezing continent of Antarctica. These black and white birds live in large groups or colonies. There are about 40 emperor penguin colonies on Antarctica. In total, there are about 400,000 birds.
   These birds spend the summer swimming in the ocean in search of food such as fish and squid. Penguins are not able to fly, but they are excellent swimmers. They can dive as deep as 460 meters and hold their breath for up to 20 minutes. But when summer ends, so does this easy time spent by the water. The penguins jump out of the water and onto the ice. They know it is time to find a mate and reproduce.
   In order to mate, the penguins must travel many kilometers inland from the ocean. They do this to find a safe area to spend the many months needed to produce and develop an egg. They must find an area with some shelter from the freezing winds.