Dear Mr. Tom, 

I am one of your neighbors who is living in the house which has the green gate. Lunar New Year festival is approaching, everyone hope to make their house decorative to celebrate Tet. Unfortunately, there are many bags of rubbish lying in front of my house. My family members are really angry when seeing them, especially when we know that your son is the person who threw them. I look forward to that after receiving this letter, you might give your son advices so that my house will be nicer to celebrate Tet. 

Thank you very much for reading my letter. 

Best regards, 

(your name).