科学家在研究七鳃鳗如何用吸盘状的嘴附着在鱼类身上。

Scientists are studying how the ___lamprey uses its sucker-like mouth to attach to fish.

那个债主就像条吸血鱼，死死缠着他不放。

The creditor clung to him like a ___lamprey, refusing to let go.