这位侦探不得不隐藏她的身份以有效调查此案。

The detective had to hide her ___identity to investigate the case effectively.

为了保护她的安全，这位证人被赋予了新的身份。

The witness was given a new ___identity to ensure her safety.

他在机场因为身份误认被警察拦下了。

He was stopped by the police because of a ___identity mix-up at the airport.