自然世界：虎鲸真面目 Natural World - Killer Whales: Beneath the Surface (2013)认领

　　The killer whale was long feared as a sea monster until, in May 1964, one was brought into captivity for the first time. This spawned a journey of discovery into the killer whale's true nature. 　　It quickly became clear, these were not mindless killers - they were, in fact, highly intelligent social creatures. Today, our understanding is deepening still further and the latest rev...