Manners are important everywhere.People are greatly respected with good manners.However,there are some bad manners wihch we should get rid of,such as picking foul language and actions such as-cutting in line,not saying excuse me (when needed) and RUDENESS,peeing in public at the subway station,talking loudly on cell phones,cursing,and spitting.
Now let's take spitting in public as an example.It is not only not decent,but also spread germs and thus does harm to the environment.
So we do have to have good manners rather than the bad ones everywhere,including in public.