A. ON B. FROM C. AT D. IN XV. READ THE PASSAG...

24. A. on B. from C. at D. in XV. Read the passage below and choose the best answer (A, B, C or D) to each question. When we are children, our siblings - our brothers and sisters - are our first friends and first enemies. At the end of life, they are often our oldest friends and oldest enemies. The effect of sibling relationships in childhood can last a lifetime. Many experts say that the relationship among thems explains a great deal about family life, especially today when brothers and sisters often spend more time with one another than with their parents. Studies have shown that sibling relationships between sister-sister pairs and brother-brother pairs are different. Sister pairs are the closest. Brothers are the most competitive. Sisters are usually more supportive of each other. They are more talkative, frank, and better at expressing themselves and sharing their feelings. On the other hand, brothers are usually more competitive with each other. Experts agree that the relationship among siblings is influenced by many factors. For example, studies have shown that both brothers and sisters become more competitive and aggressive when their parents treat them even a little bit differently from one another. But parental treatment is not the only factor. Genetics, gender, life events, people and experiences outside the family all shape the lives of siblings. It was discovered that children dislike watching their siblings fight, they respond to arguments by taking sides-supporting one sibling and punishing the other.