_____ playing dumb with teachers. They know very well their students.

A．It’s no use

B．There’s no use

C．It’s no need

D．There’s no need

男，55岁，上腹隐痛1年余，进食后缓解， 3小时前突发上腹剧痛，剑突下压痛、反跳痛，最可能的诊断是

A．胃溃疡恶变

B．胃扭转

C．消化道穿孔

D．消化道出血

E．胃平滑肌肉瘤