a lie detector的用法和样例：
- Do you think it is ok to use a lie detector?
- An instrument that simultaneously records changes in physiological processes such as heartbeat, blood pressure, and respiration, often used as a lie detector.
- A debate over this began in 1966 when a lie detector expert, Cleve Backster, connected a plant to a polygraph (lie detector).
- He tried to varnish over the truth with a lie.
- He is so naive as to believe such a lie.