如图所示,平静的水面上有一座石桥,桥孔看上去是原形的。当水面上升时,看到桥孔的形状的是下图中的
A.
B.
C.
D.
答案:B
胃穿孔的典型X线表现特征是()
A.胃泡扩张
B.膈下游离气体
C.双侧横膈抬高
D.肠管扩张
E.胃内有液平
Only after they had carried out over ten experiments ______ the decision.
A.they reached
B.they reach
C.did they reach
D.do they reach