1. Moscow and St Petersburg are the most popular places with tourists. There are lot of interesting museums and monuments there, Lake Baikal is another popular destination in Russia,2.. People usually stay in hotels. There are also other cheaper accomodations such as youth hostels and camping sites.3. I sometimes go to Moscow. Once I was in St Petersburg, a beautiful historic place. And I have a dream to visit Baikal one day. I mostly prefer to stay in hotels because they are very comfortable. Camping sites can be nice if you travel with a big company of friends who like to stay out of doors most of the time.По третьему вопросу дала два варианта, т.к. не понятно речь идет об интересных местах или месте проживания.