Elder Dink: refers to the elderly who have not had children and have not adopted children after marriage. Which of the following belong to the elderly Dink? ["Uncle Ding never married and lived in his sister's house. After his sister and brother-in-law died, he found a wife. Unexpectedly, the wife left him first.", '5-year-old Uncle Zhao, the only child who died in a car accident 10 years ago, and his wife left him again last year. He feels lonely.', 'Cai has never been born after marriage and is unwilling to adopt a child. She is not too confused. Her biggest fun every day is to watch TV shows with her pet dog.', 'Li is unmarried, has a dry daughter, does not live together, because of disability, can only live semi-self-care, the community often sends volunteers to take care of her life.']