阅读下面材料，从各题A、B、C、D中选出能回答所提问题或完成所给句子的最佳答案。
Hello, everyone. I'm Meng Hua. I'm from China. I live in Qingdao. My family is very large. In my family, my grandfather's father is the oldest one. He is now ninety-nine years old. My grandfather is eighty years old. And my grandmother is eighty-two years old. They have four children, my uncle, my father, and my aunts. I'm their grandson. My parents have two children, my sister and I. I have four cousins. Now, I'm a student in No.10 Middle School. And my sister is only five years old. My parents are both teachers. They love my family very much. We go to the park every morning. My mother says that it can help us keep healthy.