Dialog yang mencakup attention,giving opinion ,asking opinion ,understanding ?

attention: teacher: attention please, attention please
               student : yes,ma'am
asking opinion : a: what do you think of my picture ?
                          b : it's beautiful
giving opinion : a: i think this food is nice,isn't it ?
                         b: i don't think so.i think it's very sour
understanding:a:Do you understand what she mean?
                        b: yes i do