给下列句子排序，将正确的序号填在下面的方框里。  

A. Fine, thank you.        

B. She is my aunt.

C. It is my family photo.    

D. How are you, Liu Tao?

E. Is this your mother?      

F. What's that?

G. No, she isn't.            

H. Who is she?

安全的体位转换使动作之间既流畅，又保证安全，坐姿通常转换（）。