男性，23岁。2天来排柏油便6次，今晨呕吐咖啡色物入院。平素间断上腹痛，空腹时明显，无肝病史。查体：血压60/40mmHg，脉搏130次／分。下列处理措施最优先的是（）

A.急诊胃镜检查并镜下止血

B.冰盐水洗胃

C.口服去甲肾上腺素冰盐水止血

D.静脉注射止血药

E.补充血容量

An inflatable liferaft should be manually released from its cradle by（）.

A.cutting the straps that enclose the container

B.removing the rubber sealing strip from the container

C.loosening the turnbuckle on the securing strap

D.pushing the button on the hydrostatic release