There are lots of animals on the earth. What is the biggest animal of all? The whale is.  A blue whale weighs more than a hundred tons. Whales live in the sea, but they are not fish. They are mammals and must have air to breathe. The babies drink milk from the mother's body. Every spring, groups of whales swim hundreds of kilometers to warm places. Each group goes to the same place every year. The mothers take very good care of their babies. Whales are a gentle kind of giant. They always live together and help each other. They "talk" to each other in the water with a high noise that sounds like singing. Yet people kill over a hundred whales a day. They kill them to make many things. The whale dies very slowly and in great pain. Some ships kill every whale they can find, even mother whales and babies. If things go on like this, there will be no young whales to grow up and no mother whales to have more young. Whales can live  _  .
in the sea on the land in the river A and B