The whale is a warm-blooded,
air-breathing animal, giving birth to its young alive, sucking them—and like all
mammals, originated on land. There are many front flippers (鳍状肢), used for
steering and stability, are traces of feet. There are many {{U}} {{U}}
1 {{/U}} {{/U}}of this. Its immense strength is {{U}} {{U}}
2 {{/U}} {{/U}}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 {{U}} {{U}} 3 {{/U}} {{/U}}400 horsepower. One
specimen was reported to have towed (拖) a whaling vessel for seven hours at the
{{U}} {{U}} 4 {{/U}} {{/U}}of eight knots (节).
An enraged whale will {{U}} {{U}} 5 {{/U}} {{/U}}a ship. A
famous example of this was the fate of Whaler Essex, {{U}} {{U}} 6
{{/U}} {{/U}}was sunk off the coast of South America early in the last
century. More recently, steel ships have {{U}} {{U}} 7 {{/U}}
{{/U}}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 {{U}} {{U}} 8 {{/U}} {{/U}}of whales is their diving
ability. The sperm whale dives to the bottom for his {{U}} {{U}} 9
{{/U}} {{/U}}food, the octopus (章鱼). In that search he is known to go as far
down as 3,200 feet, where the {{U}} {{U}} 10 {{/U}} {{/U}}is
1,400 pounds, to a square inch. Doing so he will {{U}} {{U}} 11
{{/U}} {{/U}}underwater long as one hour. Two special skills are involved in
this storing up enough {{U}} {{U}} 12 {{/U}} {{/U}}(all whales
are air-breathed)and tolerating the great change in pressure. Just how he does
it scientists have not {{U}} {{U}} 13 {{/U}} {{/U}}. It is
believed that some of the oxygen is stored in a special {{U}} {{U}}
14 {{/U}} {{/U}}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
compensating mechanism that {{U}} {{U}} 15 {{/U}} {{/U}}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.