Old Church Slavonic is the oldest recorded language of the Slavic group.

He is known as an expert in psychoanalysis.

Japan's gross national product is the third highest in the world.

His father was diagnosed with schizophrenia in the past.

He was diagnosed with schizophrenia.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.