how do american students greet their teachers in class?

[sky753]

hi everyone :)
in china at the beginning of each class.esp in high school and elementary school ,students always stand up to greet their teachers to show their respect. for example ,in english class in the morning , teachers often say "good morning,class" and the students stand up ,greeting "good morning ,teacher"
my questions is in the same case what would the american students do?
thank you!

[Tdol]

I teach adults and they don't stand up.