n the middle 在中间；在中部
in the middle of 在…中间
例句：
① A baby is wobbling in the middle of the yard.
一个小孩正在院子中间蹒跚学步.摘自《21世纪大英汉词典》
② In the middle of the bridge,his old car spluttered out.
在过桥走到桥中间时,他的那辆破车劈啪响着熄了火.摘自《21世纪大英汉词典》
③ He finally rummaged out her reply in the middle drawer of his desk.
他最后从写字台中间抽屉里翻找出她的复信.