The Ansei era was an important period in Japanese history.

He is tackling his job with all his might and sincerity.

This town implemented a municipal organization and officially became a city.

He has a deep interest in domestic affairs.

I eat raw fruit every day.

He is thinking of learning shoemaking techniques.

The four tones of Chinese language increase the difficulty of pronunciation.

The Holocene, in geology, is the most recent geological epoch, lasting from about 10,000 years ago to the present.

He is suffering from acquired immunodeficiency syndrome.

Calculating the value of secant, one of the trigonometric functions, is difficult.