选出下列各题四个选项中的字母所含元音音素不同的那一个。

(     )1. A. I don't want to buy any books.  
           B. I have enough money for these books.
           C. I have paid for these books.  
           D. I can't buy these interesting books without money.  
(     )2. A. I often use your ruler.  
           B. I like your ruler.
           C. I used my ruler, not yours.  
           D. I have no ruler and have to use yours.
(     )3. A. Please turn the truck to the right.
           B. Let's turn down the light.
           C. It's very dark outside at right.
           D. The light should be turned on because it's dark.
(     )4. A. Xao Jun put the ball behind the door.  
           B. Xao Jun pointed to the blackboard.
           C. Xao Jun put the ball at the back of the door.  
           D. Xao Jun cleaned the door and the floor.
(     )5. A. John lives below the building.
           B. John lives on the top floor.  
           C. John brings ten flowers to the building.  
           D. John's room is on the fourth floor.