He received the letter challenging him to a duel and began preparing for the duel.

This cell is dividing very actively.

He threw the ball.

He understands that the Earth is a sphere.

He was throwing a ball in the park.

He told me the whole story of the incident.

The stratum granulosum of the skin is formed by the accumulation of keratinocytes.

Learning about the culture of specific Asia is very interesting.

The doctor recommended a blood test to check my liver function.

This high-functionality smartphone has many convenient features.