He is suspected of being involved in the illegal trade of narcotics.

He learned how to make a potion from an old book.

He went to the hospital because of a drug rash.

My eyes were hurting, so I used eye drops.

I am planning to go to Inner Mongolia, an autonomous region of China, next week.

I have been to Outer Mongolia.

I have been to Chicago.

The Paleogene period was a very important time in the history of the Earth.

He likes to take a walk in the park at dusk.

I specialize in pharmacology research.