Amy is a biologist working at a marine （海洋的） park. These kinds of parks provide fun and education for tens of thousands of people each year.
Amy takes care of many animals in the park, but she also does important research. As she observes the animals that she looks after, she learns more about their needs and behavior. This information helps the animals in the park, but it can also be used to protect other members of the species（物种） in the wild.
It's hard work to look after these animals. Their needs often change according to different hours of the day. So Amy must depend on her science knowledge and good number sense to help her make the right decisions all day long.
Even though dolphins spend much of their time underwater, they are mammals. This means that they must come to the surface to take in air. Dolphins give birth to their young. They're not hatched from eggs. Just like all other mammals, mother dolphins must nurse, or feed milk to their babies.
Amy and her team know this first﹣hand. One of their dolphins recently gave birth. A baby dolphin is not small, either. It was almost 1 meter long the day it was born. A big dolphin usually eats about 4% of its body weight in food every day. Amy knows that a mother dolphin that is nursing needs twice the food. So when the baby dolphin was born, Amy immediately doubled the mother's food every day.
