1、The shark's dorsal fin was cut off by the fisherman.
鯊魚的背鰭被漁夫割了下來。

2、The first dorsal fin is black at the front.
第一個(gè)（刺背鰭是在前面的黑。

3、His dorsal fin was down and his huge pectorals were spread wide.
它的脊鰭朝下耷拉著，巨大的胸鰭大張著。

4、Its sail-like first dorsal fin provides stability while swimming.
帆狀的第一背鰭在游動(dòng)時(shí)提供了穩(wěn)定性。

5、Its dorsal fin was in front of me. I was screaming for help.
它的背鰭就在我的前面，我尖聲呼救。

6、Now he speeded up as he smelled the fresher scent and his blue dorsal fin cut the water.
它聞到了這新鮮的血腥氣，此刻正加快了速度，藍(lán)色的脊鰭劃破了水面。