根据下列短文内容，在短文后的空格处填上一个恰当的词，使短文完整、通顺。

       Hello, I'm Jeff. I'm an English boy. But now I   1  in China. I'm a student in Chongqing No. One

Middle School. At school, I like English and P.E. Every afternoon, I play pingpong   2  my Chinese

friends. Oh, I also like   3  .On weekends I often go to movies with my friends. My   4  actors are Cheng

Long, Zhou Runfa and Li Lianjie. Their English  5  are Jackie Chan, Chow Yun-fat and Jet Li. I think   6  movies are all very exciting. Mary is my good friend. She's an English girl. She's in China,  7  .She

likes Beijing Opera. She often goes to  8   Beijing Opera with her parents. She says she learns a lot  9  

Chinese history from Beijing Opera. Oh, do you  10  Beijing Opera,too? Can you tell me ? Thank you.

蛋白质的特性是 [ ]

A．遇吲哚酚试剂褪色      

B．遇双缩脲试剂呈紫色

C．遇吲哚酚试剂变蓝色    

D．遇双缩脲试剂褪色