Is manner on the decline among teenagers?

呃，这个……
你可以说很多方面啊，不过我不知道hk具体的情况，就说说我的想法吧，你斟酌一下
1.teenagers nowadays are becoming too pround to say thanks to those who offer help which is universally considered good manners.
2.some teenagers have lost the respect for the elder,say,not to give up their seats to them when on aboard,not to be polite when confronting them or even do sth. offensive.
3.other manners such as table manners ,fades away among teenagers as time goes on

我就想到这三点啊 看能不能帮到你啊