警方使用测谎仪来帮助判断嫌疑人是否在说真话。

The police used a ___polygraph to help determine if the suspect was telling the truth.

警方决定对嫌疑人进行测谎以确保他证词的真实性。

The police decided to conduct ___polygraphs on the suspect to verify the truthfulness of his testimony.