An old friend from the US whom I was looking forward to staying with , telephoned from the airport to tell me that he had arrived . I was still at the   46   at that time , but I had got everything ready for his arrival . After letting him know where my house was，I told him that I had left the   47   under the door—mat（门垫）.   48   I was likely to be home rather late , I told him to go into the   49   and help himself to food and drink .