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.

He was a bit dimwitted, so I had to repeat the explanation several times.

I really think he's a dimwit.

The summer vacation ended in the blink of an eye.

He is an intersex person, possessing both male and female gender characteristics.

Interstellar travel is still a realm of dreams for mankind.

This book has beautifully colored interleaves.