什么是表面波?
参考答案:
当介质表面受到交变应力作用时,产生沿介质表面传播的波称为表面波。
男性,50岁,间断上腹痛2年,疼痛发作与情绪、饮食有关。查体:上腹部轻压痛。胃镜:胃窦皱襞平坦,黏膜粗糙无光泽,黏膜下血管透见,应考虑的诊断是
A.胃癌B.急性胃炎C.消化性溃疡D.慢性萎缩性胃炎E.慢性浅表性胃炎
—Did you meet our English teacher in the library?
— _______. I met her in the office. [ ]
A. Yes, I did
B. No, I didn't
C. Yes, I didn't
D. No, I did