Keijiro is my best friend.

He chose to serve a second master by working hard.

I learned the meaning of 'ichi ni ten' in the classical Japanese class.

I accidentally dropped the eye drops from the second floor.

He trains his biceps at the gym every day.

His speech was full of hendiadys expressions, which captivated the listeners.

The Triassic period is one of the geological ages, referring to the period from about 252 million years ago to about 251 million years ago.

He was affected by secondary effects.

Binary operation is one of the basic concepts in algebra.

This two-dimensional array represents students in each row and subjects in each column.