下列关于增值税的税收优惠的表述正确的有（）。

A.销售自产的综合利用生物柴油实行增值税先征后退政策

B.自2012年1月1日起，免征蔬菜流通环节增值税

C.以人发为原料生产的假发实行增值税即征即退50%的政策

D.对会议展览地点在境外的会议展览服务免征增值税

句型转换。

1. Betty does her homework at night. (改为否定句)

    Betty _______ _______ her homework at night

2. My father will get back from Beijing in two days. (对划线部分提问) 

   _______ _______ _______ your father get back from Beijing?

3. A donut is five yuan. (对划线部分提问) 

   _______ _______ _______ a donut?

4. Mr Brown asked his friends to have dinner. (改为一般疑问句) 

   _______ Mr Brown _______ his friends to have dinner?

5. There isn't anybody in the room. (改为同义句)

    There _______ _______ in the room.

6. That's a scary movie. (改为感叹句)

    _______ _______ _______ movie that is!