31.By the time we _____the airport, the plane_____.

A．arrived at; had taken off

B．had got to; took off

C．got to; had taken away

D．arrived at ; had taken away

下列关于脓胸治疗说法不正确的是：（）

A.首先取脓液做涂片及培养，并结合临床经验用药

B.按照治疗效果、细菌培养和药敏试验结果调整用药

C.急性期不宜注射用药，必要时可以胸腔内注射（限用于包裹性厚壁脓肿）

D.慢性脓胸患者应采取外科处理