a sea monster的用法和样例：
- The daughter of Cepheus and Cassiopeia and wife of Perseus,who had rescued her from a sea monster.
- Ships are disappearing all over the world and it is believed to be caused by a sea monster.
- People say that there is a sea monster in a lake in Scotland. They call it the Loch Ness Monster.
- A huge sea monster in Norwegian legend.
- Greek mythology) son of Zeus and Dana who slew the Gorgon Medusa (with the help of Athena and Hermes) and rescued Andromeda from a sea monster.