The emergency signal for fires is sounded on the ship’s whistle and general alarm as（）.

A.a continuous ringing for 10 seconds

B.one short ring followed by one long ring

C.two long rings of at least 20 seconds

D.a continuous ringing until the fire is extinguished

男性，30岁。2小时来突发右侧胸痛伴呼吸困难。既往有肺结核病史。查体见大汗，口唇发绀，气管向左移位。

该患者右胸部的体征是

A．语颤增强

B．叩诊呈鼓音

C．可闻及支气管呼吸音

D．可闻及胸膜摩擦音