Whales live in the ocean, but they are not fish. They are warm-blooded mammals and must have air to breathe. The babies are born alive and drink milk from the mother's body. It took millions of years for the whale to develop as it is today. Every spring groups of whales swim hundreds of kilometers to warm places to bear their young. Each group goes to the same place every year. The mothers take very good care of their babies. The fully grown whales are very gentle and playful with each other, and with humans. They “talk” to each other with a high noise that  sounds beautiful. This“talking” can be heard for more than 300 kilometers in open waters. Yet humans kill over a hundred whales a day. They kill them to make whale oils and a lot of other things. Killing them is a modern business with modern machines and even harpoons( 鱼叉炮) that explode( 爆炸) inside the whales. A whale dies very slowly and in great pain. Some ships kill every whale they can find, even the mothers and babies. Then there are no young whales to grow up or to bear more young. 小题1:A commonly mistaken belief is that ____. A．whales are mammals B．whales must have air to breathe C．whales' babies drink milk D．whales are fish 小题2:In the passage “mammals” refer to ____. A．the animals which live in water B．the animals which have wings and feathers C．the animals which are fed on their mothers' milk D．the things which live in earth and have no backbones 小题3:Every spring each group of whales ____. A．swim only a few kilometers B．return to the same place as they did before C．go to different places D．go to cold places to bear their young 小题4:When whales talk, it sounds like ____. A．talking B．whispering C．quarreling D．singing 小题5:Every year humans kill ____ all over the world. A．nearly forty thousand whales B．less than four million C．about four thousand whales D．about four thousand whales