fracture of posterior wall of frontal sinus

例句：

1. 1.He fell and fractured his arm.
   他摔倒了，手臂骨折了。
2. 2. The car's engine has a crack in the dashboard.
   这辆车的引擎仪表盘有裂痕。
3. 3.The old tree had several fractures from years of use.
   这棵老树因为多年使用而出现了多处裂痕。