听力原文:W: I know why that child grows so tall for his age of four. His mother requires him to drink a cup of milk every night before going to beD. M: That may not be the reason. Have you ever seen his father who is close to 2 meters tall? Q: What contributes most to the child's height according to the man? (15) A.Milk. B.Sleep. C.ExercisE. D.Genes.