十二指肠球后壁溃疡常见()。
A.十二指肠球部溃疡周边黏膜充血水肿所致
B.十二指肠球部溃疡反复发作瘢痕形成或粘连所致
C.急性穿孔
D.慢性穿孔
E.癌变
参考答案:D
He's going to France in August, and staying ______ September. [ ]
A. at
B. in
C. until
D. for
预防钻孔弯曲的措施有哪些?