The Greatest Mystery of Whales
The whale is a warm-blooded, air-breathing animal, giving birth to its young alive, ing them—and, like all mammals, originated on land. There are many 1 of this. Its front flippers (鳍状肢), used for steering and stability, are traces of feet.
Immense strength is 2 into the great body of the big whales, and in fact most of a whale"s body is one gigantic muscle. The blue whale"s pulling strength has been estimated 3 400 horsepower. One specimen was reported to have towed (拖) a whaling vessel for seven hours at the 4 of eight knot (节).
An angry whale will 5 . A famous example of this was the fate of Whaler Es, 6 was sunk off the coast of South America early in the last century. More recently, steel ships have 7 their plates buckled (使弯曲) in the same way. Sperm whales (抹香鲸) were known to seize the old-time whaleboats in their jaws and crush them.
The greatest 8 of whales is their diving ability. The sperm whale dives to the bottom for his 9 food, the octopus (章鱼). In that search he is known to go as far down as 3,200 feet, where the 10 is 1,400 pounds to a square inch. Doing so he will 11 underwater as long as one hour. Two special skills are involved in this storing up enough 12 (all whales are air-breathed)and tolerating the great change in pressure. Just how he does it scientists have not 13 . It is believed that some of the oxygen is stored in a special 14 of blood vessels, rather than just held in the lungs. And it is believed that a special kind of oil in his head is some sort of a compensating mechanism that 15 adjusts the internal pressure of his body. But since you can"t bring a live whale into the laboratory for study, no one knows just how these things work. The Greatest Mystery of Whales