hǎiyáng / shēngwùxué / kèshàng / lǎoshī / ràng / wǒmen / guānchá / shāyú / yóudòng / shí / xiōngqí / de / biànhuà

海洋生物学课上，老师让我们观察鲨鱼游动时胸鳍的变化。

In marine biology class, the teacher asked us to observe how a shark's pectoral fins change as it swims.