A. 大血管 B. 关节处 C. 头部 D. 下肢
A. 确定目标 B. 确定计划前提条件 C. 挖掘可行方案 D. 拟定政策
A. 正确 B. 错误
A. a vessel meeting another head-on B. a vessel overtaking another in a narrow channel C. a vessel crossing the course of another D. the give-way vessel in a crossing situatio