insertion of polyethylene into middle ear

例句：

1. 1.The surgeon inserted the needle into the patient's arm.
   外科医生将针头插入病人的手臂。
2. 2. She inserted a key into the lock to open the door.
   她把钥匙插进锁孔来打开门。
3. 3. The carpenter inserted the bolts into the wall before painting it.
   木匠在粉刷墙壁之前，将螺栓插入墙中。