Orcas, also known as killer whales, are big dolphins with sharp teeth. They have black and white colors on their bodies. You can find them in many oceans around the world, from very cold places to warm waters. These animals are at the top of the food chain and they eat different things depending on where they live. They might eat fish, sharks, or even other sea creatures like seals. Orcas live together in family groups called pods and they have their own way of hunting. They also talk to each other in special ways that can be different in each group. Some people think this is like having their own culture. We are not sure how many types of orcas there are and some types might be in trouble because they are losing food and places to live. They also get sick from pollution and sometimes people catch them for sea parks. In the United States, some orcas are protected because they are in danger. Orcas don't usually hurt people in the wild, but there have been some accidents with orcas in sea parks. People from different places think of orcas in different ways, like spirits or scary animals. A lot of people have started calling them orcas instead of "killer whales." The name "orca" comes from an old word that means something like "from the underworld."

The environment is everything around us on Earth. It has things that are alive like plants and animals, and things that are not alive like rocks and soil. It also has air and weather. The environment can take care of itself without much help from people. There are many parts to the environment, such as air, water, and different kinds of weather. People study the environment to learn about it and help take care of it. They also study problems that can happen in the environment, like changes in the weather. Some people study how to keep the environment safe for everyone.

When a plane or boat has problems over the ocean, special teams come to help. This is called air-sea rescue. Teams use different things like seaplanes, helicopters, and boats to save people. Both soldiers and regular people can do these rescues. There are rules about how to save people in the water. These rules are written in a big book. Saving people during a war is very important. It helps pilots feel safer when they fly over water. Knowing that someone will come to save them makes them feel better. Soldiers started using boats that could fly to save people a long time ago, in World War I. Later, people had better tools and could save people farther away from the shore. During World War II, helicopters were used for the first time to rescue people. Helicopters can stay in one spot in the air, which is very helpful for these missions.