When I went to bed   21   night, I fell asleep immediately. I must have been tired because I had been working so   22   for several hours. So I forgot to close the windows before  getting into bed. If I had remembered, the thief would not have got   23  . But he was given a perfect opportunity to enter the house. The next time, I work late I will lock the house carefully.    A policeman came to see me   24   the theft. "I've been told to investigate," he said, "so I want to ask you some questions." "First, how did the thief get in ?" I told him that I had left the window   25  . "You should be more careful, "he said. "If people looked after their houses properly, we wouldn't have much work to do." (1)、

A:hard 

B:in 

C:open 

D:about 

E:last