食管内金属异物首选的X线检查方法是（）

A.硫酸钡造影法

B.钡棉造影法

C.胸部正侧位平片

D.胸部断层像

E.CT

第二节：开放作文（15分）

请根据下面提示，写一篇短文。词数不少于50。

In your spoken English class, your teacher shows you the following picture. You are asked to deseribe the picture and explain how you understand it.