legal ground
Article 72 of the Civil Procedure Law, conditions and obligations of witnesses.
All units and individuals who know the case have the obligation to testify in court. The person in charge of the relevant unit shall support the witness to testify. People who cannot express their meaning correctly cannot testify.
Article 73 of the Civil Procedure Law, witnesses testify in court.
Upon notification by the people's court, the witness shall testify in court. Under any of the following circumstances, with the permission of the people's court, written testimony, audio-visual transmission technology or audio-visual materials may be used to testify:
Unable to appear in court for health reasons;
(2) Being unable to appear in court due to long distance and inconvenient transportation;
(3) Unable to appear in court due to force majeure such as natural disasters;
(four) other legitimate reasons can not appear in court.