In Marxism, the concept of constant capital plays an important role.

This concept is difficult.

He is deeply immersed in the study of Marxism.

He worked hard to accomplish his goals.

His role is the team leader.

Health is very important.

His opinion is very important.

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

His role is to fulfill his responsibilities as a leader.

Gender roles are an important element in defining individual behavior in society.