1)by
2)of
3)in
4)a,-,of,on
5)with(неуверенна)
1) The book has been written by a group of authers.
2) I am fond of my new friend.
3) My mother lives in the country.
4) There is a vase with flowers and a glass of water on the table.
5) I know the girl with whom you have been dancing two hours.