上消化道出血时对病因诊断最有帮助的检查方法是()
A.选择性腹腔动脉造影
B.内窥镜检查
C.X线钡餐检查
D.胃黏膜活检
E.核素检查
参考答案:B
If you want to given a rise, you must be prepared to make a ____ contribution to the business.[ ]
A. passive
B. diverse
C. secure
D. positive
什么叫剖视图?