a witness who has knowledge not normally possessed by the average person concerning the topic that he is to testify about
双语例句
Any expert witness who intentionally makes a false evaluation shall assume legal responsibility therefrom. 鉴定人故意作虚假鉴定的，应当承担法律责任。
The corroboratory department and the expert witness shall submit a written conclusion of corroboration and sign or seal the corroboration bill. 鉴定部门和鉴定人应当提出书面鉴定结论，在鉴定书上签名或者盖章。
