He is a bit thickheaded, so he didn't notice her feelings.

We should recycle to prevent environmental pollution.

Have you ever had an indirect kiss with him?

A gap is created in the wall of the building due to the earthquake.

He made time to meet his friends by squeezing it into gaps in his busy schedule.

A gap gradually developed between him and me.

The White House is the official residence of the President of the United States.

He went to the archives to find important information.

He is majoring in Korean studies at university.

I am majoring in Korean studies at university.