增生型肠结核最重要的X线表现是
A.肠壁铺卵石样充盈缺损B.肠段狭窄、收缩与变形C.线样征D.铅管征E.跳跃征
参考答案:B
They _____ some books from the library last week.[ ]
A. lent
B. lends
C. borrowed
D. buy
摆动导杆机构的极位夹角与导杆摆角的关系为()