expert witness

例句：

1. 1. He hired anexpert witness to testify in court.
   他聘请了一位专家证人在法庭上作证。
2. 2. The expert witness was expected to provide valuable insights into the case.
   这位专家证人被期望提供对案件有价值的见解。
3. 3.The expert witness's testimony helped to clarify the legal issues at hand.
   这位专家证人的证词有助于澄清手头的法律问题。