Warning devices are needed to prevent dolphins and whales from becoming entangled in the nets.需要安装警示装置以防海豚和鲸鱼被网缠住。The dolphin was enmeshed in/by the net.那只海豚被网缠住了。His legs became caught in the net, and he was unable to get himself free.他的双腿被网缠住了，无法抽身。His legs became tangled in the net, and he was unable to free himself.他的双腿被网缠住了，他无法脱身。