2008年职称英语真题之综合类A级完型填空:  
 
第6部分：完型填空(第51～65题，每题1分，共15分)

   下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。

                    The Greatest Mystery of Whales

     The whale is a mammal(哺乳动物)一warm—blooded，air-breathing，giving birth to its young alive，sucking them—and，like all mammals，originated on land，There are many signs of this．________(51)front flippers(鳍肢)，used for steering and stability，are traces of feet。

     Immense strength is built 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________ (52)has been estimated at 400 horsepower．One specimen was reported to have________ (53) a whaling vessel for seven hours at the________ (54)of eight knots．
     An enraged whale will attack a ship．A famous________ (55)of this was the fate of whaler Essex，which was sunk________(56)the coast of South America early in the last century．More recently ,steel ships have had their plates buckled(扭曲变形)in the same way．Sperm whales were known to________ (57)the old—time whaleboats in their jaw sand crush them．  

     The greatest mystery of whales is their diving ability．The sperm whale can
________ (58)the bottom for his favorite food，the octopus(章鱼)．________ (59)that search he is known to go as far down as 3，200 feet，where the pressure is 1，400 pounds，to the square inch．Doing________ (60)he will remain submerged(水下的)as long as one hour．Two feats(绝技)are involved in this：storing up enough________ (61)(all whales are air-breathed)and withstanding the great change in pressure．Just________(62)he does it scientists have not determined．It is believed that some of the oxygen is stored in a special system of blood vessels，rather than just held in the lungs。And________ (63)is believed that a special kind of oil in his head is some sort of compensating mechanism that automatically adjusts the internal pressure of his body．But________ (64)you can’t bring a live whale into the laboratory for study，no one________(65)just how these things work.

 51 A Their       B It's            C Theirs      D Its

 52 .A strength     B width          C height      D length

 53. A eaten       B crashed         C towed(拖)   D lifted
 
 54. A distance     B rate            C voyage     D sail

 55. A picture      B film            C example    D book