Revolving door

[babangida]

I never really thought about what the revolving door is for. It even seemed unnecessary to me at times. Then I thought, what's the use of this? In fact, it also has a structure that prevents people from walking. More like harm than good. But I found out what it was and decided it would be right. The aim is to prevent the cold air from entering outside and to protect the warm air inside. I think it's quite reasonable.