左侧卧位可使腹痛减轻提示何种疾病（）。

A.十二指肠淤滞症

B.胰体癌

C.反流性食管炎

D.胃黏膜脱垂

E.胃溃疡

On July 1^st, 1921, the red boat on South Lake in Jiaxing ________ the birth of the Communist Party of China,   

which marked a new start for Chinese people.

A．witnessed

B．gave

C．experienced

D．founded