共用题干 The Greatest Mystery Of WhalesThe whale is a warm-blooded,air-breathing animal,giving birth to its young alive, sucking them一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 knots (节).An angry whale will_________(5)a ship.A famous example of this was the fate of whaler Essex,_________(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,toa square inch.Doing so he will_________(11)underwater long as one hour. Twospecial 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 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. _________(1)
A.aspects B.signs C.ways D.reasons正确答案B
