In a state of weightlessness, objects float freely.

The study of gravitational waves contributes greatly to our understanding of the universe.

He invented an anti-gravity device.

This chemical reaction is accelerated by catalysis.

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.

Interstellar travel is still a realm of dreams for mankind.

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

The doctor said there is a problem with my interosseous.