Unfortunately, when I dropped in, Professor Smith ________, so we only had time for a few words.

A．has just left

B．had just left

C．just left

D．was just leaving

6岁男孩，右腹股沟肿物2年，于平卧时消失，站立时出现，哭闹时更加明显，用手可回纳入腹腔，透光试验阴性，可能诊断是（）

A.右侧精索鞘膜积液

B.股疝

C.腹股沟直疝

D.腹股沟斜疝

E.右侧隐睾