食道异物的并发症有()
A.食管穿孔或损伤性食管炎
B.颈部皮下气肿、纵隔气肿
C.食管周围炎
D.纵隔炎
E.大出血
参考答案:A, B, C, D, E
— Have you ever been to Mount Gu, Michael?
— No. I've _____ been there. [ ]
A. ever
B. already
C. never
对于老黄土地基,按()确定容许承载力。