句型练习。
1. The shirt cost me only 50 yuan.   （就划线部分提问）
                                       did the shirt cost?
2. That dictionary cost me $10 . (同义句)
I                    10                    for that dictionary. 
3. My parents should allow me to study with friends.（改为被动句）
I should                                     to study with friends.
4. I used to be a naughty boy. (改成一般疑问句)
              you                              be a naughty boy?
5. The little boy cried because he was hungry.（就画线部分提问）
                                     the little boy cry?