用牛肉膏作培养基能为微生物提供：（）
A．C源
B．N源
C．生长因素
D．A，B，C都提供
参考答案：A
He tried to deal with the ever-in- creasing burden of his work, but finally____ and had to take a complete rest. [ ]
A. broke away
B. broke up
C. broke down
D. broke out
女，49岁，脐周疼痛近1个月，大便有时稀。体检：脐周有压痛，结合图像，最可能的诊断为（）
A.胃体炎
B.胃体癌
C.胃窦炎
D.胃窦癌
E.胃溃疡
