临床疑为胰腺癌,首选的影像学检查方法().
A.CT
B.MRI
C.超声
D.血管造影
E.ERCP
参考答案:C
— I remember you were a talented pianist at college. Can you play the piano for me?
— Sorry, I ________ the piano for years. [ ]
A. don't play
B. wasn't playing
C. haven't played
D. hadn't played
下列选项中,()是侵染性病害的病原。
A.污水
B.有毒气体
C.寒潮
D.病原物