My parents prefer boys to girls, and I feel wronged and sad. Please give me some advice.

You are an adult, and your two younger brothers are still so young. You should help your parents share some worries. Your parents didn't give you anything, which is very, very nothing, because you are an adult compared with your brother, so you should learn to love your brother. Talk to your parents more and share their troubles. It's more than you can bear to have three children. Remember at all times that you are the boss and you should share something. Don't haggle like a child.