对仅挨声门下的“气管异物”患者紧急开放气道的处理措施是（）

A.全麻气管插管

B.面罩加压供氧

C.气管切开

D.喉罩置入

E.纤支镜引导插管

— John seems happy, even though his wife left him and he lost his job.

— I think he __________ to put on a brave face.

A．will try

B．has tried

C．had tried

D．is trying