急性呕吐伴上腹痛、发热、皮肤发黄,应考虑()。
A.急性胃肠炎
B.急性胆囊炎合并胆道梗阻
C.急性胰腺炎
D.肠梗阻
E.胃癌
参考答案:B
I've become good friends with several of the students in my school _____ I met in the English speech
contest last year. [ ]
A. who
B. where
C. when
D. which
关于X线照片影像的形成要素不包括()
A.照片的密度
B.照片的感度
C.照片的对比度
D.照片的锐利度
E.照片的放大与变形