This is the 3755th most frequent Chinese word.
车门
Car door.
车门 is used as a noun meaning 'car door' in the context of accessing the car cabin.
打开车门，我们就可以进入车内。
Open the car door, and we can enter the car.
车门 serves as the subject of the sentence, emphasizing the condition of being locked.
车门被锁住了，所以我们无法打开它。
The car door is locked, so we cannot open it.
车门 acts as the location where the described action of replacement is performed.