When I hear that song, old memories come to mind.

He completed the project in a week.

I'm always busy during the daytime, and I only have time to rest at night.

He had been working overseas for an extended period of time.

The theory of spacetime is an important part of physics.

Mr. Mashiwa is my best friend.

Sakakima is my best friend.

Mr. Azama is my best friend.

The summer vacation ended in the blink of an eye.

Interstellar travel is still a realm of dreams for mankind.