He works digging out coal.

It's difficult to remember new words.

Carbohydrates are important as a source of energy.

This problem is simple, so it can be solved quickly.

I don't really like carbonated drinks.

My father was transferred far away from home, and was separated from his family.

My father went to Tokyo on a solo assignment.

We made a plan to explore the unexplored areas of Africa.

He likes to write short stories.

There are many words in English that are the same in singular and plural forms.