to the backbone 彻底
A：Helen is going out with Tom.
B：I hope not. Tom is a liar to the backbone.
A：How come?
B：He never tells anything true.
A：海伦正和汤姆交往。
B：我可不希望这样。汤姆是个十足的骗子。
A：何以见得？
B：他从来就没讲过真话。
