十二指肠球溃疡最常发生于（）
A.穹隆部
B.大弯侧
C.小弯侧
D.前壁
E.后壁
参考答案：E
I would appreciate very much if you could send me a few copies of the mechanic design of your new model.
A．it
B．that
C．this
D．you
建筑基桩采用声波透射法，其声波发射与接收换能器的水密性应满足（）MPa水压不渗水。（）
A.1.0
B.1.5
C.2.0
D.2.5
