This croc-relative had a sleek, streamlined body that helped reduce drag in the water, making it much more hydrodynamic.

这只鳄鱼亲戚拥有光滑、流线型的身体， 有助于减少水中的阻力，使其更具水动力。

Sharks come in many different shapes, too, although most sharks have streamlined bodies shaped like torpedoes to help them glide more easily through the water.

不同种类的鲨鱼形态各异，绝大部分鲨鱼的体型都是流线型，这种鱼雷式的形状有助于它们在水里轻松穿行。

Large oily livers lend buoyancy to their streamlined bodies, and while trunk muscles of bony fishes attach directly to their skeletons, those of sharks also join to their skin.

在游动时更加节省能量，它们巨大的油质肝脏为流线型的身体提供浮力，与其它硬骨质的鱼类不同。

Birds that are better fliers have more streamlined bodies, and their organs are more tightly packed, which puts a limit on how wide an egg you can squeeze through that egg-making tube.

飞得更好的鸟类身体更多呈流线型，而且它们的器官更紧密地堆积在一起，这限制了蛋可以通过的制蛋管的宽度。