kē / xué / jiā / rèn / wéi / jù / yá / shā / céng / jīng / shēng / huó / zài / wēn / nuǎn / de / hǎi / yáng / zhōng科学家认为,巨牙鲨曾经生活在温暖的海洋中。Scientists believe that megalodons once lived in warm oceans.