Look!One of the children _____ in the river.

A．was swimming

B．is swimming

C．are swimming

D．were swimming

患者女性，31岁。心慌、失眠、多汗、食欲亢进、体重减轻半年余。查体：T36.7℃，P114次/分，R18次/分，BP110/70mmHg，颈部增粗。甲状腺大部切除术后12小时，出现颈部憋胀，呼吸困难，发绀。立即采取的措施是（）.

A.拆开缝线，清除血肿

B.气管切开

C.给氧

D.吸痰

E.到手术室行急诊手术

F.气管插管