骨囊肿可以自愈,保守治疗无效时可行刮除植骨术。()
参考答案:对
溃疡病急性穿孔最有诊断意义的是()。
A.腹痛突然加重
B.出现腹膜炎体征
C.肠鸣音减弱或消失
D.休克征象
E.气腹征
In a crossing situation,the stand-on vessel should normally().
A.take action to cross ahead of the other vessel
B.take action to pass astern of the other vessel
C.maintain course and speed
D.change course and increase speed