______ around the cultural relics for almost an hour, we got together under a big tree for a short break.

A．Having shown

B．Having been shown

C．To show

D．To be shown

一患者因车祸致口腔颌面部多处裂伤伴下颌骨多发性骨折，出现神志不清、口唇发绀及三凹征时的紧急处理应是（）

A.吸氧

B.清创缝合

C.骨折复位

D.人工呼吸

E.气管切开