查体时鉴别腹股沟斜疝与直疝最有意义的是

A．疝的外形

B．透光试验

C．疝内容物是否进入阴囊

D．疝囊是否位于腹壁下动脉外侧

E．回纳后压迫腹股沟浅环，疝块是否能够复出

Which of the following cities is NOT located in the Northeast, U.S.（）

A. Huston

B. Boston

C. Baltimore

D. Philadelphia