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.

He has an absolute pitch, so his musical talent is very high.

In organic chemistry, cyclodecane is a cyclic saturated hydrocarbon consisting of ten carbon atoms.

In this chemical reaction, cyclooctadecane is the main product.

Pentadecane is produced in this chemical reaction.

In organic chemistry, a cycloalkane is a compound with a structure in which carbon atoms are linked in a ring.