arriving at a strange-looking house,he showed me into a large,bright clean room.it had a green wall,a brown floor and soft lighting.sunddenly,the wall moved-it was made of trees！i found later that their leaves prvided the room with much-needed oxygen.then wangping flashed a swith on a computer screen,and a table and some chairs rose from under the flooras if by magic.why not sit down and eat a little？he said.you may find