根据句意，用括号中所给词的适当形式填空。

( )1. Let ______  try, and I will understand.  (I)                                                                      

( )2. I have met many kind teachers in the past three years. I think I am a ______ girl. (luck)  

( )3. Life to everyone is only ______, we shouldn't waste time. (one)                      

( )4. Give up  ______! It's bad for your health. (smoke)                                      

( )5. Li Na is one of the best tennis  ______ in the world. (play)                           

食管癌早期症状最常见的是（）

A.胸骨后疼痛

B.吞咽困难

C.食物或黏液反流

D.进粗食时有暂时性胸骨后停留或异物感

E.消瘦