a shameless liar and scoundrel的用法和样例：
- He is a shameless liar.
- She laid about him, calling him a liar and a cheat.
- It's my considered opinion that he is a liar and a cheat.
- Do I love him? Who wouldn't love a cheat, a liar and a scoundrel?
- One boy called the other a liar and they set to.