orifice of superior vena cava

例句：

1. 1.The surgeon carefully removed the tumor from the patient's orifice.
   外科医生小心翼翼地从病人的孔洞中取出肿瘤。
2. 2.The scientist found an unusual orifice on the surface of the moon.
   科学家在月球表面发现了一个不寻常的孔洞。
3. 3.The engineer designed a new orifice for the ventilation system.
   工程师为通风系统设计了一个新的孔洞。