—Who helped Jessie with her English?

—_______, she taught herself. [ ]

A. Anybody

B. Somebody

C. Nobody 　　

D. Everybody

单纯性小肠梗阻最典型的X线表现为（）

A.膈下新月状气体影

B.阶梯状液平

C.小肠胀气扩张

D.咖啡豆征

E.足球征