贲门失弛缓症常见并发症有（）
A.支气管扩张
B.食管癌
C.膈上憩室
D.支气管肺炎
E.食管支气管瘘
参考答案：A, B, C, D
—Why do you want to be a teacher?
—Because it is ______. [ ]
A. excited
B. exciting
C. For, exciting
D. For, excited
水土流失的危害有哪些？
