食管支架置入术的适应证是（）
A.食管气管瘘
B.食管癌术后吻合口狭窄
C.原发性食管癌
D.心功能衰竭
E.肾衰竭
参考答案：A, B, C
Alice has gone to the classroom and she didn't say _____. [ ]
A. when did she come back
B. when would she be back
C. when she came back
D. when she would be back
肾脏兼有内分泌功能，能分泌一些生物活性物质。（）
