By the time some scientists ____ the lost towns, they ____ an awesome historical site.

A．had found, had found

B．found, found

C．found, had found

D．had found, found

10个月女孩，因频繁吐奶、排血样便2次就诊，诊断为肠套叠，经空气灌肠复位症状消失，半天后又排血样便，无呕吐，此时应如何处理（）

A.手术切除坏死肠段

B.口服止血药物

C.抗感染

D.第二次空气灌肠复位

E.向家人解释为正常情况，无需处理