_81____________ (arrive) at a strange-looking house, Wang Ping showed me into a large, bright clean room. It had a green wall, a brown floor and soft lighting. Suddenly the wall moved—it was made _82______ trees. I found later _83______ their leaves provided the room _84______ much-needed oxygen. Then Wang Ping flashed a switch _85______ a computer screen, and a table and some chairs rose _86______ under the floor as if by magic. “Why not sit down and eat a little?” he said, “You may find this difficult as it is your first time travel trip. Just relax, since there is nothing _8