【简答题】

  I worried about the missed bag all the evening.    
I tried to remember exact what I had done from the    
time I left the store until at the time I got home. I     
remembered whether I had looked at the bag while I    
was having lunch. So I must have it when I left the    
store. I remembered showing it to a friend on the bus.   
But I had the bag then. I came directly from the bus   
to my house, and I must have forgotten it on the bus. I     
was in hurry to get off and forgot to check the p ackages    
lying on the floor. I should be much careful next time.