With old age, his eyesight gradually deteriorated.

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.

The human immunodeficiency virus destroys the immune system, making the body unable to fight disease.

It is important to learn about the prevention and treatment of the human immunodeficiency virus.

His efforts were like a mantis trying to stop a chariot, he couldn't achieve any results.

We have equipped everything necessary for the trip.

This wire is bent into a hook shape.

His words can be understood as a metaphor.

He was captured by the enemy.

He was deeply grieving the death of his family.