1. There has long been…
long 表完成时 = for a long time, for long, 一般在助动词后
2. superstition : 迷信
3. 同位语从句 …mariners that ….
4. formation : 阵形 defensive : 防御型的 offensive : 进攻型的
5. however = no matter how
6. intelligent : 聪明 credit : 给…颁发奖赏 credit with
7. on the occasions (场合),接后置定语时只能用 when, 不能用 where
8. out of curiosity:出于好奇 out of instinct 出于本能 out of conscience 出于良心
9. bow waves of a ship 船头滑过的波浪 ,乘风破浪前进
10. waterlogged : 浸透的 mattress 木排,柴排
There has long been a superstition among mariners that porpoises will save drowning men by pushing them to the surface, or protect them from sharks by surrounding them in defensive formation. Marine Studio biologists have pointed out that, however intelligent they may be, it is probably a mistake to credit dolphins with any motive of life-saving. On the occasions when they have pushed to shore an unconscious human being they have much more likely done it out of curiosity or for sport,as in riding the bow waves of a ship. In 1928 some porpoises were photographed working like beavers to push ashore a waterlogged mattress. If, as has been reported, they have protected humans from sharks, it may have been because curiosity attracted them and because the scent of a possible meal attracted the sharks. Porpoises and sharks are natural enemies.