拔牙术中最常见的并发症是（）

A.牙龈损伤

B.牙折断

C.邻牙或对颌牙折断或损伤

D.下颌骨骨折

E.下牙槽神经或舌神经损伤

句型转换。

1. It's half an hour's walk from our school to the park. (对画线部分提问)

    _______ _______is it from your school to the park?

2. She usually goes to work by bus. (对画线部分提问)

    _______ _______she usually_______to work?

3. My grandfather is very healthy these years. (对画线部分提问)

     _______ _______your grandfather these years?

4. How about going for a walk? (改为同义句)

     _______ _______for a walk?

5. We go to the beach three times a year. (对画线部分提问)

     _______ _______do you go to the beach?