I lost my house key.

Have you seen my keys?

My key is a very important character.

The swing door was opening and closing in the wind.

Please be careful as the platform door is closing.

This train has a selective door operation feature.

He is using that coat from winter to spring.

He was gently petting the cat.

He repeated my words, acting as if they were his own opinion.

He poked around the room, trying to find what he was looking for.