Article 73 of the Civil Procedure Law of People's Republic of China (PRC) * * * 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: (1) Unable to appear in court due to 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.