In organic chemistry, the concept of cis-trans isomers is important.

The study of filterable pathogens is an important part of virology.

In organic chemistry, the concept of conformational isomers is very important.

A tesseract is a four-dimensional geometric shape.

A 5-cell is a simple convex polytope in four dimensions.

He explained the importance of studying while young, saying 'If you do not study when you are young, it will be difficult to learn when you are old.'

Today is your special day, happy birthday.

The Mus musculus is widely distributed around the world.

He feels it takes time to acquire new skills, but Rome wasn't built in a day.

I heard a nakiusagi (a type of rabbit) crying in the park.