— Do you know       ?        

— In the 6th century.[ ]

A. who is the abacus invented

B. when the abacus is invented

C. when was the abacus invented

D. when the abacus was invented

某女，24岁，3天前患上感，此后突然左耳内剧烈疼痛伴听力下降，纯音测听示左耳平均气导听阈为35 dB HL。查左耳鼓膜红肿，其上有大小不等的紫色血疱，外耳道皮肤充血。最可能的诊断是：（）

A．急性化脓性中耳炎

B．颈静脉球体瘤

C．大疱性鼓膜炎

D．中耳癌

E．分泌性中耳炎