B). identify the type of situation (formal, neutral, informal) and introduce:
a close friend / to your mother
a groupmate / to the english teacher
a senior colleague / to your friend
your teacher / to your parents
your bank manager / to your brother
yourself / to a new groupmate (colleague)
one guest at your party / to another
2. Oh, hi groupmate! (Neutral) / Hello Miss Elena.(formal)
3. Hi, senior colleague.(neutral) / Sup, Alex.(neutral)
Дальше не знаю