Penguins live both in the water and on land. They have flippers （脚蹕） to help them swim and they cannot fly. Some penguins can stay underwater for twenty minutes. Penguins eat things they can catch in the water like shrimp （虾） and fish. The penguins are afraid of sharks. So, they protect themselves by staying in large groups. Their black backs also make them hard to be seen from above the water. Their white stomachs make them hard to be seen from below the water. The largest penguins are about 121cm tall and weigh about one-hundred pounds.
