пожимать руки- to shake hands (When Americans are introduced for the first time, they usually shake hands...)
целовать в щеку- to kiss smb on the cheek (...when they meet friends or relatives they haven't seen for a while, they sometimes kiss them on the cheek. )
представляться по имени- to introduce by name (Waiters in restaurants will often introduce themselves by name)
обед «в складчину»- a "pot luck dinner" (Many people take a bottle of wine or some flowers when they are invited to dinner at someone's home, at a "pot luck dinner, all the guests bring something to eat. )
свадьба- a wedding (Traditional party occasions are a birthday, moving to a new house, a wedding, New Year's Eve, and the Fourth of July.)
приехать на десять минут позже- to arrive ten minutes late (When you are invited to dinner, it is usually to arrive ten or fifteen minutes late, this gives the hosts time to finish their preparations.)
повод для вечеринки- party occasions (Traditional party occasions are a birthday, moving to a new house, a wedding, New Year's Eve, and the Fourth of July. )
2. There are a lot of new students at school.
3. David is from New York.
4. Yesterday she invited us to the party.
5. Did you go to the countryside in October?
По-моему, так)