阅读短文，判断正误。
Hello! I'm Linda. I have a good e-friend. Her name is Zhang Yun. Her English name is Betty. She is a Chinese girl, but she lives in the UK with her parents. Her father is a doctor and her mother is a teacher. She is ten years old. She call me big sister. She is good at English. She likes Chinese and I also like Chinese. She likes singing and playing basketball. This is my good e-friend. Do you want to know more?
上单调递减，则实数
满足的条件是（ ）
