ostium sinus cornarii

例句：

1. 1. The ostium of the tunnel is blocked by debris.
   隧道的开口被碎片堵塞了。
2. 2. The surgeon removed the ostium of the wound with sutures.
   外科医生用缝合线移除了伤口的开口。
3. 3. The ostium of the river is visible from the bridge.
   从桥上可以看到河流的开口。