食管腐蚀伤发生后,食管镜检查应在()。
A.伤后立即进行
B.受伤2周后的缓解期
C.经钡餐透视确诊为食管狭窄时
D.出现并发症时
E.以上均正确
参考答案:B
— Do you ask why I am learning English?
— Yes, I mean, what are you going to do with it? Are you going to be a teacher of English
or something like ?[ ]
A. it
B. him
C. that
D. such
在下列四种速度分布图中,切应力的大小不为0并且不随坐标y发生变化的是()。
A.图(a)
B.图(b)
C.图(c)
D.图(d)