In some countries children's behavior areis restricted by many rules or traditions
behaviors are / behavior is
There has been much disputes over this questionissue and my view is that there is no absolute right or wrong on both approaches.
Good introduction; it follows the right structure
Childrens
... I have seen many people make this mistake and may be this is a typo you made.... Then right word is "children" which itself is plural. The singular term is "child"
Childrens living in those the countries with strong traditional atmosphere always need to follow rules.
.... when you say "those", it tends to refer to something that you have introduced previously to this sentence. But in this case there is no such reference.
Children have to say"good morning" to their parents every morning.
... "morning" is the shorten form :D
Children should greet their parents every morning.Before starting the meals, they are required to say their parents' names or even all order relatives' names to show their respects to them.
... Is this thanking your parents or ancestors for providing food for you? ... very interesting and I'm curious to know :)