Carbon dioxide is one of the main causes of global warming.

This factory is emitting a large amount of sulfur dioxide.

This diode only allows current to flow in one direction.

The grammar of 'Jou-nidan' is an important part in learning Japanese.

I hurried down the lower two steps.

Kenjiro is my best friend.

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.