在 + (Noun) + 里面
里面 (lǐmiàn) is a location noun meaning "inside" or "within," used to indicate that something is in the interior of a space or object. It typically follows a noun or appears after the preposition 在.
冰箱里面还有一些牛奶和鸡蛋。
Bīngxiāng lǐmiàn hái yǒu yīxiē niúnǎi hé jīdàn.
There is still some milk and eggs in the refrigerator.
箱子里面装的全是旧照片。
Xiāngzi lǐmiàn zhuāng de quán shì jiù zhàopiàn.
The box is filled entirely with old photos.
别在房间里面抽烟,出去抽吧。
Bié zài fángjiān lǐmiàn chōuyān, chūqù chōu ba.
Don't smoke inside the room — go outside to smoke.