骶骨

例句：

1. 1.He sat on the edge of the bed with his legs crossed.
   他坐在床边，双腿交叉坐着。
2. 2. The doctor performed a thorough examination of her lumbar spine.
   医生对她的腰椎进行了彻底的检查。
3. 3. She was diagnosed with a rare condition affecting the sacrum.
   她被诊断出患有一种罕见疾病，影响骶骨。