He revealed that half the officers in a key unit failed a polygraph test last year. 据他透露，半数某关键部门的警官都没能通过去年的测谎鉴定。
A polygraph test consists of four to six sensors attached to a person's body to record breathing rate, pulse, blood pressure and perspiration. 测谎器包括四至六个感应器，连结在人体以记录呼吸、脉搏、血压与流汗情形。
