1.I (was sitting/am sitting/sat) on a bench and reading an article when John (was coming up/came up/had come up) to me.
2.When Sara (arrived/was arriving/have arrived) at the airport, she saw some flight attendants for the first time in her life.
3.Jessica (had watched/was watching/watched)a film when she heard somebody knocking on the door.
4.Yesterday Nick (was going/have gone/went)to the library, then he (have had/was having/had)lunch, and after that he (was meeting/met/had met)his supervisor.
5.Andrew (was spraining/sprained/have sprained)his ankle when he (was fleeing/flee/fled)from the police officers.
6.When the manager (was entering/entered/had entered)the office, everybody (danced/was dancing/were dancing).
7.On holidays we (have gone/were going/went)hiking, (were swimming/swam/have swum)in the lake and visited the historic centre of the town.

А) Brings, brought, bringing, bringing, being born, brought; Translating, translated, translate, translating, translated, being translated, translated; Buys, buying, bought, bought, bought, bought; Receiving, receiving, receiving, received, obtained, being obtained, received; Read, read, read , reading, reading.
Б) written, giving, talking, asked, asked, told, published, working, opening, taking, lost, made, standing, walking, stepping, looking, built, seeing, wrгiting this, drinking, drawing, going, taking, looking, being, forgotten, playing, broken, baked, roasted, tested, selected, boiling interested.

There are lots of holidays and celebrations Russia both national and foreign. Even though many Russians celebrate world holidays, such as St.Valentine’s Day, April Fools, Halloween and others, there are a number of purely Russian national holidays, which are celebrated only in Russia. These holidays emphasize the spirit of nation and support folk traditions. One of the most interesting holidays in Russia takes place at the end of February to celebrate the end of winter. The holiday lasts for a week which is known as a Shrovetide. In Russia this holiday is called “Maslennitsa”. People traditionally eat lots of pancakes on this holiday and burn the scarecrow saying farewell to winter snow. Another traditionally Russian celebration takes place on January 7th, which is an Orthodox Christmas. People visit their relatives on this day carrying rice pudding with raisins, which is called “kutya”. Many young and single girls try to read their fortune on the night of 6th and 7th January. Russian weddings are also very joyous events and they differ a lot from other countries. There is a special person on Russian weddings called “tamada” who entertains the guests by various toasts and games. Every June many Russians celebrate the holiday called “The night of Ivan Kupala”. People traditionally weave the wreaths from wildflowers, make the bonfires and swim in lakes on the night of this day. Извини меньше не смог